U.S. patent application number 17/352168 was filed with the patent office on 2021-10-14 for magnetically enhanced high density plasma-chemical vapor deposition plasma source for depositing diamond and diamond-like films.
This patent application is currently assigned to IonQuest Corp.. The applicant listed for this patent is IonQuest Corp.. Invention is credited to Bassam Hanna Abraham.
Application Number | 20210317569 17/352168 |
Document ID | / |
Family ID | 1000005681508 |
Filed Date | 2021-10-14 |
United States Patent
Application |
20210317569 |
Kind Code |
A1 |
Abraham; Bassam Hanna |
October 14, 2021 |
Magnetically Enhanced High Density Plasma-Chemical Vapor Deposition
Plasma Source For Depositing Diamond and Diamond-Like Films
Abstract
A method of sputtering a layer on a substrate using a
high-energy density plasma (HEDP) magnetron includes positioning
the magnetron in a vacuum with an anode, cathode target, magnet
assembly, substrate, and feed gas; applying unipolar negative
direct current (DC) voltage pulses from a pulse power supply with a
pulse forming network (PFN) to a pulse converting network (PCN);
and adjusting an amplitude and frequency associated with the
plurality of unipolar negative DC voltage pulses causing a
resonance mode associated with the PCN. The PCN converts the
unipolar negative DC voltage pulses to an asymmetric alternating
current (AC) signal that generates a high-density plasma discharge
on the HEDP magnetron. An increase in amplitude or pulse duration
of the plurality of unipolar negative DC voltage pulses causes an
increase in the amplitude of a negative voltage of the asymmetric
AC signal in response to the PCN being in the resonance mode,
thereby causing sputtering discharge associated with the HEDP
magnetron to form the layer from the cathode target on the
substrate. A corresponding apparatus and computer-readable medium
are disclosed.
Inventors: |
Abraham; Bassam Hanna;
(Millis, MA) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
IonQuest Corp. |
Mansfield |
MA |
US |
|
|
Assignee: |
IonQuest Corp.
Mansfield
MA
|
Family ID: |
1000005681508 |
Appl. No.: |
17/352168 |
Filed: |
June 18, 2021 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
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17127527 |
Dec 18, 2020 |
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17352168 |
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16261514 |
Jan 29, 2019 |
10913998 |
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17127527 |
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15917046 |
Mar 9, 2018 |
10227692 |
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16261514 |
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15261119 |
Sep 9, 2016 |
9951414 |
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15917046 |
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16025928 |
Jul 2, 2018 |
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17127527 |
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PCT/US2017/048438 |
Aug 24, 2017 |
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16025928 |
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62482993 |
Apr 7, 2017 |
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Current U.S.
Class: |
1/1 |
Current CPC
Class: |
H01L 21/76879 20130101;
C23C 14/3485 20130101; H01L 21/76882 20130101; C23C 14/0057
20130101; H01L 23/53238 20130101; C23C 14/354 20130101; H01J
37/32825 20130101; H01J 37/3417 20130101; H01J 37/3455 20130101;
H01J 37/345 20130101; H01L 21/2855 20130101; H01J 37/3435 20130101;
H01L 23/5226 20130101; C23C 14/35 20130101; C23C 14/0605 20130101;
H01L 21/76843 20130101; H01J 37/321 20130101; H01J 37/3467
20130101; C23C 14/345 20130101; H01J 37/3464 20130101; H01L
21/76871 20130101; H01J 37/3405 20130101; C23C 14/14 20130101; H01J
37/3426 20130101; H01J 37/3452 20130101 |
International
Class: |
C23C 14/35 20060101
C23C014/35; H01J 37/34 20060101 H01J037/34; C23C 14/34 20060101
C23C014/34; H01L 21/285 20060101 H01L021/285; H01L 21/768 20060101
H01L021/768; H01L 23/522 20060101 H01L023/522; H01L 23/532 20060101
H01L023/532; H01J 37/32 20060101 H01J037/32; C23C 14/00 20060101
C23C014/00; C23C 14/06 20060101 C23C014/06; C23C 14/14 20060101
C23C014/14 |
Claims
1. A method of sputtering a layer on a substrate using a
high-energy density plasma (HEDP) magnetron, the method comprising:
positioning the HEDP magnetron in a vacuum with an anode, a cathode
target, a magnet assembly, the substrate, and a feed gas; applying
a plurality of unipolar negative direct current (DC) voltage pulses
from a pulse power supply to a pulse converting network (PCN), the
PCN comprising at least one inductor and at least one capacitor;
and adjusting an amplitude and a frequency associated with the
plurality of unipolar negative DC voltage pulses causing a
resonance mode associated with the PCN, the PCN converting the
unipolar negative DC voltage pulses to an asymmetric alternating
current (AC) signal that generates a high-density plasma discharge
on the HEDP magnetron with pulse current densities in a range of
about 0.1 to 20 A/cm2, the asymmetric AC signal operatively coupled
to the cathode target, the asymmetric AC signal comprising a first
negative voltage and a positive voltage followed by a second
negative voltage, the second negative voltage generating plasma for
use during a subsequent first negative voltage, an increase in
amplitude or pulse duration of the plurality of unipolar negative
DC voltage pulses causing an increase in amplitude of at least one
of the negative voltages of the asymmetric AC signal in response to
the PCN being in the resonance mode, thereby causing sputtering
discharge associated with the HEDP magnetron to form the layer from
the cathode target on the substrate.
2. The method, as defined by claim 1, further comprising applying a
negative bias voltage to the substrate, thereby attracting
positively charged ions sputtered from the cathode target to the
substrate, a value of the negative bias voltage being in a range of
about 10 V to 500 V.
3. The method, as defined by claim 1, wherein the cathode target
comprises a hollow shape.
4. The method, as defined by claim 1, wherein the feed gas
comprises a noble gas, the noble gas comprising at least one of Ar,
Ne, Kr, Xe, He.
5. The method, as defined by claim 1, wherein the feed gas
comprises a mixture of a noble gas and a reactive gas, the reactive
gas being reactive with atoms associated with the cathode
target.
6. The method, as defined by claim 1, wherein the feed gas
comprises a mixture of a noble gas and a gas comprising atoms
associated with the cathode target.
7. The method as defined by claim 1, wherein the cathode target
comprises a flat shape.
8. The method, as defined by claim 1, further comprising rotating
the cathode target at a speed in a range of about 1 to 400
revolutions per minute.
9. The method, as defined by claim 1, wherein the cathode target
comprises at least one of the following elements: B, C, Al, Si, P,
S, Ga, Ge, As, Se, In, Sn, Sb, Te, I, Tl, Pb, Bi, Sc, Ti, Cr, Mn,
Fe, Co, Ni, Cu, Zn, Y, Zr, Nb, Mo, Tc, Ru, Rh, Pd, Ag, Cd, Lu, Hf,
Ta, W, Re, Os, Ir, Pt, Au, La, Ce, Pr, Nd, Pm, Sm, Eu, Gd, Tb, Dy,
Ho, Er, Tm, Yb, Be, Mg, Ca, Sr, B a.
10. The method, as defined by claim 1, wherein the substrate
comprises at least one of a portion of an automotive engine, valve,
injector head, crank shaft, bushing, bearing, sprocket, cell phone,
mobile phone, iPhone, iPod, touch screen, cutting tool, drill bit,
insert for cutting tool, semiconductor wafer with a diameter in a
range of about 25 mm to 450 mm, razor blade, film used to
manufacture an electronic memory device, RAM, PCRAM, ReRam.
11. The method, as defined by claim 1, wherein the first negative
voltage comprises a first amplitude and the second negative voltage
comprises a second amplitude, the second amplitude being less than
the first amplitude.
12. An apparatus that sputters a layer on a substrate using a
high-energy density plasma (HEDP) magnetron, the apparatus
comprising: a HEDP magnetron configured to be positioned in a
vacuum with an anode, a cathode target, a magnet assembly, the
substrate, and a feed gas; a pulse power supply, the pulse power
supply providing a plurality of unipolar negative direct current
(DC) voltage pulses; and a pulse converting network (PCN)
comprising at least one inductor and at least one capacitor
configured to cause a resonance discharge between the pulse power
supply and the HEDP magnetron, the PCN converting the unipolar
negative DC voltage pulses to an asymmetric alternating current
(AC) signal that generates a high-density plasma discharge on the
HEDP magnetron with pulse current densities in a range of about 0.1
to 20 A/cm2, an amplitude and a frequency of a plurality of
unipolar negative DC voltage pulses adjusted to cause a resonance
mode associated with the PCN, the asymmetric AC signal operatively
coupled to the cathode target, the asymmetric AC signal comprising
a first negative voltage and a positive voltage followed by a
second negative voltage, the second negative voltage generating
plasma for use during a subsequent first negative voltage, an
increase in amplitude or pulse duration of the plurality of
unipolar negative DC voltage pulses causing an increase in
amplitude of at least one of the negative voltages of the
asymmetric AC signal in response to the PCN being in the resonance
mode, thereby causing sputtering discharge associated with the HEDP
magnetron to form the layer from the cathode target on the
substrate.
13. The apparatus, as defined by claim 12, further comprising a
negative bias voltage power supply, the negative bias voltage power
supply operatively coupling a negative bias voltage to the
substrate, thereby attracting positively charged ions sputtered
from the cathode target to the substrate, a value of the negative
bias voltage being in a range of about 10 V to 500 V.
14. The apparatus, as defined by claim 12, wherein the cathode
target comprises a hollow shape
15. The apparatus, as defined by claim 12, wherein a value of a
magnetic field disposed parallel to a surface of the cathode target
is in a range of about 150 to 1000 G.
16. The apparatus, as defined by claim 12, wherein the feed gas
comprises a noble gas, the noble gas comprising at least one of He,
Ar, Kr, Xe, Ne.
17. The apparatus, as defined by claim 12, wherein the feed gas
comprises a mixture of a noble gas and a reactive gas, the reactive
gas being reactive with atoms associated with the cathode
target.
18. The apparatus, as defined by claim 12, wherein the feed gas
comprises a mixture of a noble gas and a gas comprising atoms
associated with the cathode target.
19. The apparatus, as defined by claim 12, wherein the cathode
target comprises a flat shape.
20. The apparatus, as defined by claim 12, further comprising a
magnet assembly, the magnet assembly rotating at a speed in a range
of about 1 to 400 revolutions per minute.
21. The apparatus, as defined by claim 12, wherein the first
negative voltage comprises a first amplitude and the second
negative voltage comprises a second amplitude, the second amplitude
being less than the first amplitude.
22. A computer-readable medium storing instructions that, when
executed by a processing device, perform a method of sputtering a
layer on a substrate using a high-energy density plasma (HEDP)
magnetron comprising: positioning the HEDP magnetron in a vacuum
with an anode, a cathode target, a magnet assembly, the substrate,
and a feed gas; applying a plurality of unipolar negative direct
current (DC) voltage pulses from a pulse power supply to a pulse
converting network (PCN), the PCN comprising at least one inductor
and at least one capacitor; and adjusting an amplitude and a
frequency associated with the plurality of unipolar negative DC
voltage pulses causing a resonance mode associated with the PCN,
the PCN converting the unipolar negative DC voltage pulses to an
asymmetric alternating current (AC) signal that generates a
high-density plasma discharge on the HEDP magnetron with pulse
current densities in a range of about 0.1 to 20 A/cm2, the
asymmetric AC signal operatively coupled to the cathode target, the
asymmetric AC signal comprising a first negative voltage and a
positive voltage followed by a second negative voltage, the second
negative voltage generating plasma for use during a subsequent
first negative voltage, an increase in amplitude or pulse duration
of the plurality of unipolar negative DC voltage pulses causing an
increase in amplitude of at least one of the negative voltages of
the asymmetric AC signal in response to the PCN being in the
resonance mode, thereby causing sputtering discharge associated
with the HEDP magnetron to form the layer from the cathode target
on the substrate.
23. The computer-readable medium, as defined by claim 22, wherein
the first negative voltage comprises a first amplitude and the
second negative voltage comprises a second amplitude, the second
amplitude being less than the first amplitude.
Description
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application is a continuation application of U.S.
application Ser. No. 17/127,527, filed Dec. 18, 2020, which is a
continuation-in-part application of U.S. application Ser. No.
16/261,514, filed Jan. 29, 2019, which is a continuation
application of U.S. application Ser. No. 15/917,046, filed Mar. 9,
2018, which is a continuation application of U.S. application Ser.
No. 15/261,119, filed Sep. 9, 2016, which claims the benefit of
U.S. Provisional Application No. 62/270,356, filed Dec. 21, 2015,
the disclosures of which are incorporated by reference herein in
their entireties. U.S. application Ser. No. 15/260,841 entitled
"Capacitive Coupled Plasma Source for Sputtering and Resputtering",
U.S. application Ser. No. 15/260,857 entitled "Electrically and
Magnetically Enhanced Ionized Physical Vapor Deposition Unbalanced
Sputtering Source", and U.S. application Ser. No. 15/261,197
entitled "Magnetically Enhanced Low Temperature-High Density
Plasma-Chemical Vapor Deposition Plasma Source for Depositing
Diamond and Diamond-Like Films" are incorporated by reference
herein in their entireties. U.S. application Ser. No. 17/127,527,
filed Dec. 18, 2020, is a continuation-in-part application of U.S.
application Ser. No. 16/025,928, filed Jul. 2, 2018, which is a
continuation-in-part application of International Application No.
PCT/US17/48438, filed Aug. 24, 2017, which claims the benefit of
U.S. Provisional Application No. 62/482,993, filed Apr. 7, 2017,
the disclosures of which are incorporated by reference herein in
their entireties.
BACKGROUND
Field
[0002] The disclosed embodiments generally relate to a
plasma-enhanced chemical vapor deposition (PE CVD) apparatus and
method and, more particularly, relate to a pulse magnetically
enhanced low-temperature high-density plasma chemical vapor
deposition (LT HDP CVD) apparatus and method.
[0003] The disclosed embodiments relate to high-power resonance
pulse technology for advanced thin film layer deposition on any
substrate. The disclosed embodiments also relate to converting a
unipolar negative direct current (DC) pulse to a high-power
resonance asymmetric alternating current (AC) pulse on a magnetron
for sputtering advanced thin films on any substrate. The disclosed
embodiments generally relate to a high energy density plasma (HEDP)
magnetically enhanced sputtering source and a method for sputtering
hard, dense, and smooth thin films on a substrate surface.
Related Art
[0004] CVD plasma sources that deposit diamond and diamond-like
coatings and films use hot filament chemical vapor deposition
(HFCVD) and microwave-assisted chemical vapor deposition (CVD)
techniques. Methods require a high temperature on a substrate and
high bias voltage in order to form a carbon film with a high
content of sp3 bonds. Accordingly, new CVD technologies are needed
that will allow depositing diamond-like carbon (DLC) films at much
lower temperatures and much lower bias.
SUMMARY
[0005] Various embodiments relate to an apparatus, method, and
system for pulse magnetically enhanced high-density plasma chemical
vapor deposition (HDP CVD) of thin-film coatings, and in
particular, diamond and diamond-like coatings.
[0006] The magnetically enhanced HDP-CVD source includes (a) a
hollow cathode target assembly connected to a power supply, which
can include a pulsed power supply, variable power direct current
(DC) power supply, variable power alternating current (AC) power
supply, radio frequency (RF) power supply, pulsed RF power supply,
high power impulse magnetron sputtering (HIPIMIS) power supply,
HIPMIS power supply with an additional pulse forming network (PFN)
or pulse converting network (PCN) to generate a high-power
resonance asymmetric pulsed AC discharge or a combination of any of
these power supplies, (b) an anode that is connected to ground, (c)
a gap between a hollow cathode target and an anode, (d) two rows of
permanent magnets or electromagnets that are positioned on top of
each other in order to generate a cusp magnetic field in the gap
between the hollow cathode and the anode, (e) a cathode magnet
assembly that can be configured to generates magnetic field lines
perpendicular to a surface of the hollow cathode target, (f) a
magnetic coupling between the cathode target magnet assembly and a
cusp magnetic field in the gap, (g) a flowing liquid that cools and
controls the temperature of the hollow cathode, (h) a cathode
magnet assembly that can be configured to generates magnetic field
lines perpendicular to a surface of the hollow cathode target and,
concentric with the hollow cathode target, another magnet assembly
forming a magnetron configuration on the surface of the hollow
cathode target, (i) an accelerating grid positioned parallel to the
surface of the hollow cathode target, (j) and a power supply
connected to the accelerating grid providing voltage for ion
acceleration.
[0007] The magnetically enhanced CVD source may include (a) a pole
piece between the two rows of magnets that are exposed to the
plasma through the gap between the hollow cathode and the anode,
(b) a pole piece positioned on top of a top row of the magnets, (c)
a gap in the anode that exposes a pole piece positioned on top of
the top row of magnets to the plasma, (d) a gas distribution
system, (e) an inductor connected between the cathode and ground to
eliminate the DC bias generated by impingement of electrons on the
powered cathode, (f) a motor that can rotate a cathode magnet
assembly, (g) a power supply connected to a pole piece, and (e) an
inductor connected between the pole piece and ground to eliminate
the DC bias generated by impingement of electrons on the powered
pole piece and, in some cases, the inductor is connected to the
pole piece on one end and to a synchronized electronic switch on
the other end and to ground.
[0008] The magnetically enhanced CVD source may include (a) a pole
piece between the two rows of magnets that is not exposed to the
plasma through the gap between the hollow cathode and the anode
protected by a shield, (b) a pole piece positioned on top of a top
row of the magnets, (c) a gap in the anode that exposes the shield
piece positioned on top of the top row of magnets to the plasma,
(d) a gas distribution system, (e) an inductor connected between
the cathode and ground, (f) a cathode magnet assembly, (g) a power
supply connected to shield piece, and (h) an inductor connected
between the shield piece and ground to eliminate the DC bias
generated by impingement of electrons on the powered shield.
[0009] The magnetically enhanced CVD source may include (a) a pole
piece between the two rows of magnets that is not exposed to the
plasma through the gap between the hollow cathode and the anode
protected by a shield, (b) a pole piece positioned on top of a top
row of the magnets, (c) a gap in the anode that exposes the shield
piece positioned on top of the top row of magnets to the plasma,
(d) a gas distribution system, (e) an inductor connected between
the cathode and ground to eliminate the DC bias generated by the
impinging of electrons on the powered cathode, (f) a cathode magnet
assembly, (g) a power supply connected to shield piece, (h) an
inductor connected between the shield piece and ground to eliminate
the DC bias generated by impingement of electrons on the powered
shield, (i) an accelerating grid positioned parallel to the surface
of the hollow cathode target, and (j) a ground power supply
connected to the accelerating grid providing voltage for ion
acceleration.
[0010] The magnetically enhanced CVD apparatus includes (a) a
magnetically enhanced CVD source, (b) a vacuum chamber, (c) a
substrate holder, (d) a substrate, (e) a feed gas mass flow
controller, and (f) a vacuum pump.
[0011] The magnetically enhanced HDP-CVD apparatus may include (a)
a DC or RF substrate bias power supply, (b) a substrate heater, (c)
more than one magnetically enhanced PVD sources, (d) a gas
activation source, (a) an additional magnet assembly positioned
between the magnetically enhanced HDP-CVD plasma source and the
substrate holder or positioned below the substrate holder. The
magnet assembly can be positioned inside or outside a vacuum
chamber.
[0012] A method of providing magnetically enhanced HDP-CVD thin
film deposition includes (a) forming a cusp magnetic field in a gap
between a hollow cathode and an anode, (b) forming magnetic field
lines perpendicular to a bottom surface of the hollow cathode, (c)
providing feed gas, (d) applying negative voltage to the cathode
target and igniting volume plasma discharge, (e) and positioning a
substrate.
[0013] The method of providing magnetically enhanced CVD thin film
deposition may include (a) heating the substrate, (b) applying a
bias voltage to the substrate, (c) applying an RF voltage to the
pole piece, (d) applying an RF voltage to the cathode target, and
(e) synchronizing the RF voltage applied to the pole piece and RF
voltage applied to the cathode target or using a common exciter
(CEX) to prevent unwanted beat frequencies. Two RF generators can
be phase-locked together to run at the same frequency and with a
fixed phase relationship between their outputs. This locking
ensures repeatable RF characteristics within the plasma.
[0014] The method of providing magnetically enhanced CVD thin film
deposition may include (a) heating the substrate, (b) applying a
bias voltage to the substrate, (c) applying an RF voltage to the
pole piece, (d) applying an RF voltage to the cathode target, (e)
synchronizing the RF voltage applied to the pole piece and RF
voltage applied to the cathode target or using a common exciter
(CEX) to prevent unwanted beat frequencies, (f) an accelerating
grid positioned parallel to the surface of the hollow cathode
target, and (g) a power supply connected to the accelerating grid
providing voltage for ion acceleration. Two RF generators can be
phase-locked together to run at the same frequency and with a fixed
phase relationship between their outputs. This locking ensures
repeatable RF characteristics within the plasma.
[0015] A magnetically enhanced chemical vapor deposition (CVD)
apparatus includes a hollow cathode target assembly; an anode
positioned on top of the hollow cathode target assembly, thereby
forming a gap between the anode and the hollow cathode target
assembly; a cathode magnet assembly; two rows of magnets facing
each other with the same magnetic field direction that generate a
cusp magnetic field in the gap and a magnetic field on the hollow
cathode surface with the cathode magnet assembly, the magnetic
field comprising magnetic field lines that are substantially
perpendicular to the hollow cathode target assembly; and a pole
piece positioned between the two rows of magnets and connected to a
voltage power supply, the voltage power supply generating a train
of negative voltage pulses that generates a pulsed electric field
in the gap perpendicular to the cusp magnetic field, the electric
field igniting and sustaining plasma during a pulse of the train of
negative voltage pulses, a frequency, duration and amplitude of the
train of negative voltage pulses being selected to increase a
degree of ionization of feed gas atoms.
[0016] The magnetically enhanced CVD sputtering apparatus may
include a second gap positioned inside the anode such that a
portion of the magnetic field lines forming the cusp magnetic field
cross the gap and terminate on top of a second row of magnets, and
a radio frequency (RF) power supply connected to the hollow cathode
target assembly, wherein the RF power supply generates output
voltage with a frequency in a range of about 1 MHz to 100 MHz. The
power supply may be connected to the hollow cathode target assembly
and generate output current in a range of about 20 A to 200 A. The
magnetically enhanced CVD sputtering apparatus may include a
substrate holder, and a substrate bias power supply, wherein the
substrate bias power supply is connected to the substrate holder
and generates a bias voltage on the substrate in a range of about
-10 V to -2000 V. The magnetic field in the gap may be in a range
of about 50 G to 10000 G. The cathode target material may include
carbon and/or aluminum.
[0017] A method of magnetically enhanced chemical vapor deposition
(CVD) sputtering includes providing a hollow cathode target
assembly; forming a gap between the hollow cathode target assembly
and an anode; positioning a cathode magnet assembly; generating a
cusp magnetic field in the gap such that magnetic field lines are
substantially perpendicular to the hollow cathode surface;
positioning a pole piece in the gap connected to a voltage power
supply; providing a pulsed DC power to the cathode target to ignite
and sustain volume discharge; generating a train of negative
voltage pulses using the voltage power supply; and selecting a
frequency, duration, and amplitude of the train of negative voltage
pulses to increase a degree of ionization of sputtered target
material atoms.
[0018] The method may include positioning a second gap inside the
anode such that the portion of the magnetic field lines forming the
cusp magnetic field crosses the gap and terminate on top of a
second row of magnets, and connecting a radio frequency (RF) power
supply to the hollow cathode assembly and generating output voltage
with a frequency in a range of about 1 MHz to 100 MHz. The voltage
power supply can generate output voltage in a range of about -100 V
to -3000 V. The method may include connecting a substrate bias
power supply to a substrate holder and generating a bias voltage on
a substrate in a range of about -10 V to -2000V. The magnetic field
in the gap may be in a range of about 50 G to 10000 G, and the
cathode target material may include carbon and/or aluminum.
[0019] A method of magnetically enhanced chemical vapor deposition
(CVD) sputtering includes providing a hollow cathode target
assembly; forming a gap between the hollow cathode target assembly
and an anode; positioning a cathode magnet assembly; generating a
cusp magnetic field in the gap such that magnetic field lines are
substantially perpendicular to the hollow cathode surface;
positioning a shield piece between the gap and the magnets forming
the cusp field, connecting the shield piece to a voltage power
supply; providing a pulsed DC power to the cathode target to ignite
and sustain volume discharge; generating a train of negative
voltage pulses using the voltage power supply; and selecting a
frequency, duration, and amplitude of the train of negative voltage
pulses to increase a degree of ionization of sputtered target
material atoms.
[0020] A method of magnetically enhanced chemical vapor deposition
(CVD) sputtering includes providing a hollow cathode target
assembly; forming a gap between the hollow cathode target assembly
and an anode; positioning a cathode magnet assembly, the cathode
magnet assembly can be two parts including an outer-ring with a
perpendicular field, wherein the cathode target closes the field
with the cusp field through the gap and a concentric magnetic
assembly forming a magnetron configuration on the cathode target,
the cathode inner magnetic assembly can be stationary or rotating;
positioning a shield piece between the gap and the magnets forming
the cusp field, connecting the shield piece to a voltage power
supply or grounded; providing a pulsed DC power to the cathode
target to ignite and sustain volume discharge; generating a train
of negative voltage pulses using the voltage power supply; and
selecting a frequency, duration, and amplitude of the train of
negative voltage pulses to increase a degree of ionization of
sputtered target material atoms.
[0021] A method of magnetically enhanced chemical vapor deposition
(CVD) sputtering includes providing a hollow cathode target
assembly; forming a gap between the hollow cathode target assembly
and an anode; positioning a cathode magnet assembly, the cathode
magnet assembly can be two parts, including an outer-ring with a
perpendicular field, the cathode target closing the field with the
cusp field through the gap and concentric magnetic assembly forming
a magnetron configuration on the cathode target, the cathode inner
magnetic assembly can be stationary or rotating; positioning a
shield piece between the gap and the magnets forming the cusp
field, connecting the shield piece to a voltage power supply or
grounded; providing a high-power pulsed resonance asymmetric AC
power to the cathode target to ignite and sustain volume discharge;
generating an inductively current-driven plasma; and selecting a
frequency, duration, and amplitude to optimize the resonance
asymmetric AC pulses to increase a degree of ionization of
sputtered target material atoms.
[0022] A method of magnetically enhanced chemical vapor deposition
(CVD) sputtering includes providing a hollow cathode target
assembly; forming a gap between the hollow cathode target assembly
and an anode; positioning a cathode magnet assembly; generating a
cusp magnetic field in the gap such that magnetic field lines are
substantially perpendicular to the hollow cathode surface;
positioning a shield piece between the gap and the magnets forming
the cusp field, connecting the shield piece to an RF power supply
with an inductor to ground to eliminate the DC bias generated by
impingement of electrons on the powered shield, a radio frequency
(RF) power supply connected to the hollow cathode target assembly,
wherein the RF power supply generates output voltage with a
frequency in a range of about 1 MHz to 100 MHz. The power supply
may be connected to the hollow cathode target assembly and generate
output current in a range of about 20 A to 200 A. The two RF power
supplies can be the same frequency or different frequencies If the
same frequency is used, a common exciter (CEX) can be used to
prevent unwanted beat frequencies. Two RF generators can be
phase-locked together so that the generators run at the same
frequency and with a fixed phase relationship between their
outputs. This locking ensures repeatable RF characteristics within
the plasma. The magnetically enhanced CVD sputtering apparatus may
include a substrate holder and a substrate bias power supply,
wherein the substrate bias power supply is connected to the
substrate holder and generates a bias voltage on the substrate in a
range of about -10 V to -2000 V. The magnetic field in the gap may
be in a range of about 50 G to 10000 G. The cathode target material
may include carbon and/or aluminum.
[0023] The magnetically enhanced CVD sputtering apparatus may
include a second gap positioned inside the anode such that a
portion of the magnetic field lines forming the cusp magnetic field
cross the gap and terminate on top of a second row of magnets, a
grounded shield piece positioned between the gaps and the magnets
forming the cusp field, and a radio frequency (RF) power supply
connected to the hollow cathode target assembly, wherein the RF
power supply generates output voltage with a frequency in a range
of about 1 MHz to 100 MHz. The power supply may be connected to the
hollow cathode target assembly and generate output current in a
range of about 20 A to 200 A. The magnetically enhanced CVD
sputtering apparatus may include a substrate holder, and a
substrate bias power supply, wherein the substrate bias power
supply is connected to the substrate holder and generates a bias
voltage on the substrate in a range of about -10 V to -2000 V. The
magnetic field in the gap may be in a range of about 50 G to 10000
G. The cathode target material may include carbon and/or
aluminum.
[0024] The magnetically enhanced CVD sputtering apparatus may
include a second gap positioned inside the anode such that a
portion of the magnetic field lines forming the cusp magnetic field
cross the gap and terminate on top of a second row of magnets,
positioning a grounded shield piece between the gaps and the
magnets forming the cusp field, and a radio frequency (RF) power
supply connected to the hollow cathode target assembly, wherein the
two different RF power supply generates output voltage with a
frequency in a range of about 1 MHz to 100 MHz. The two RF power
supplies may be connected to the hollow cathode target assembly by
two different frequency matching network and generate output
current in a range of about 20 A to 200 A. The magnetically
enhanced CVD sputtering apparatus may include a substrate holder,
and a substrate bias power supply, wherein the substrate bias power
supply is connected to the substrate holder and generates a bias
voltage on the substrate in a range of about -10 V to -2000 V. The
magnetic field in the gap may be in a range of about 50 G to 10000
G. The cathode target material may include carbon and/or
aluminum.
[0025] A method of magnetically enhanced chemical vapor deposition
(CVD) plasma-enhanced atomic layer deposition (PE-ALD) includes
providing a hollow cathode target assembly; forming a gap between
the hollow cathode target assembly and an anode; positioning a
cathode magnet assembly; generating a cusp magnetic field in the
gap such that magnetic field lines are substantially perpendicular
to the hollow cathode surface; positioning a shield piece between
the gap and the magnets forming the cusp field, connecting the
shield piece to an RF power supply with an inductor to ground; and
a radio frequency (RF) power supply connected to the hollow cathode
target assembly, wherein the RF power supply generates output
voltage with a frequency in a range of about 1 MHz to 100 MHz. The
power supply may be connected to the hollow cathode target assembly
and generate output current in a range of about 20 A to 200 A. The
two RF power supplies can be the same frequency or different
frequencies. If the same frequency is used, a common exciter (CEX)
can be used to prevent unwanted beat frequencies, two RF generators
can be phase-locked together so that the generators run at the same
frequency and with a fixed phase relationship between their
outputs. This locking ensures repeatable RF characteristics within
the plasma The magnetically enhanced CVD plasma-enhanced atomic
layer deposition (PE-ALD) apparatus may include a substrate holder,
and a substrate bias power supply, wherein the substrate bias power
supply is connected to the substrate holder and generates a bias
voltage on the substrate in a range of about -10 V to -2000 V. The
magnetic field in the gap may be in a range of about 50 G to 10000
G. The cathode target material may include carbon and/or
aluminum.
[0026] The magnetically enhanced chemical vapor deposition (CVD)
plasma-enhanced atomic layer deposition (PE-ALD) apparatus may
include a second gap positioned inside the anode such that a
portion of the magnetic field lines forming the cusp magnetic field
cross the gap and terminate on top of a second row of magnets,
positioning a grounded shield piece between the gaps and the
magnets forming the cusp field, and a radio frequency (RF) power
supply connected to the hollow cathode target assembly, wherein the
two different RF power supplies generate output voltage with a
frequency in a range of about 1 MHz to 100 MHz. The two RF power
supplies may be connected to the hollow cathode target assembly by
two different frequency matching networks and generate output
current in a range of about 20 A to 200 A. The magnetically
enhanced CVD plasma-enhanced atomic layer deposition (PE-ALD)
apparatus may include a substrate holder, and a substrate bias
power supply, wherein the substrate bias power supply is connected
to the substrate holder and generates a bias voltage on the
substrate in a range of about -10 V to -2000 V. The magnetic field
in the gap may be in a range of about 50 G to 10000 G. The cathode
target material may include carbon and/or aluminum.
[0027] A method of magnetically enhanced chemical vapor deposition
(CVD) plasma thruster includes providing a hollow cathode target
assembly; forming a gap between the hollow cathode target assembly
and an anode; positioning a cathode magnet assembly, the cathode
magnet assembly having a perpendicular field to the cathode target
closing the field with the cusp field through the gap; positioning
a shield piece between the gap and the magnets forming the cusp
field; connecting the shield piece to a voltage power supply or
grounded; providing pulsed DC power to the cathode target to ignite
and sustain volume discharge; generating a train of negative
voltage pulses using the voltage power supply; and selecting a
frequency, duration, and amplitude of the train of negative voltage
pulses to increase a degree of ionization of the pulsed plasma
thruster. The plasma thruster is used as a propulsion or steering
device on satellites or spaceships in a low vacuum environment,
such as space.
[0028] A method of magnetically enhanced chemical vapor deposition
(CVD) plasma thruster includes providing a hollow cathode target
assembly; forming a gap between the hollow cathode target assembly
and an anode; positioning a cathode magnet assembly, the cathode
magnet assembly having a perpendicular field to the cathode target;
closing the field with the cusp field through the gap; positioning
a shield piece between the gap and the magnets forming the cusp
field; connecting the shield piece to a voltage power supply or
grounded; providing pulsed DC power to the cathode target to ignite
and sustain volume discharge; generating a train of negative
voltage pulses using the voltage power supply; and selecting a
frequency, duration, and amplitude of the train of negative voltage
pulses to increase a degree of ionization of the pulsed plasma
thruster, an accelerating grid positioned parallel to the surface
of the hollow cathode target, and a power supply connected to the
accelerating grid providing voltage for ion acceleration.
[0029] A method of magnetically enhanced chemical vapor deposition
(CVD) pulsed ARC source includes providing a hollow cathode target
assembly; forming a gap between the hollow cathode target assembly
and an anode; positioning a cathode magnet assembly, the cathode
magnet assembly having a perpendicular field to the cathode target;
closing the field with the cusp field through the gap; positioning
a shield piece between the gap and the magnets forming the cusp
field; connecting the shield piece to a voltage power supply or
grounded; providing a DC power supply to ignite and sustain and arc
spot on the hollow cathode target and superimposing it with a
pulsed DC power to the cathode target to increase the pulsed
current in the arc spot discharge; generating a train of negative
voltage pulses using the voltage power supply; and selecting a
frequency, duration, and amplitude of the train of negative voltage
pulses to increase a degree of ionization of the evaporated
material from the hollow cathode target. The arc source produces
dense and smooth thin films on a substrate with tiny
micro-particles and, in some cases, with no micro-particles.
[0030] The disclosed embodiments relate to a high energy density
plasma (HEDP) magnetically enhanced sputtering source, apparatus,
and method for sputtering hard coatings and dense, smooth,
low-stress, thin films in the presence of high-power pulse
asymmetrical alternating current (AC) voltage waveforms. The
high-power pulse asymmetric AC voltage waveform is generated by
having a regulated voltage source with variable power feeding a
regulated voltage to the high-power pulse direct current (DC)
supply with a built-in first pulse forming network (PFN) with
programmable pulse voltage duration and pulse voltage frequency
producing at its output a train of regulated amplitude unipolar
negative voltage DC pulses with programmed pulse frequency and
duration and supplying these pulses to a second tunable pulse
forming network (PFN) or pulse converting network (PCN) including a
plurality of inductors and capacitors for pulse applications
connected in a specific format coupled to a magnetically enhanced
sputtering source. By adjusting the pulse voltage amplitude,
duration, and frequency of the unipolar negative voltage DC pulses
and tuning the values of the inductors and capacitors in the second
PFN or PCN coupled to a magnetically enhanced sputtering source, a
resonance pulsed asymmetric AC discharge is achieved.
[0031] Another method to produce a resonance pulsed asymmetric AC
discharge is to have fixed unipolar pulse power supply parameters
(amplitude, frequency, and duration) feeding a second pulse forming
network or pulse converting network (PCN), in which the numerical
values of the inductors and capacitors, as well as the
configuration, can be tuned to achieve the desired resonance values
on the HEDP source to form a layer on the substrate. The tuning of
the second PFN or PCN can be done manually with test equipment,
such as an oscilloscope, voltmeter and current meter or other
analytical equipment; or electronically with a built-in software
algorithm, variable inductors, variable capacitors, and data
acquisition circuitry. The negative voltage from the pulse
asymmetric AC voltage waveform generates high-density plasma from
feed gas atoms and sputtered target material atoms between the
cathode sputtering target and the anode of the magnetically
enhanced sputtering source. The positive voltage from the pulse
asymmetrical AC voltage waveform attracts plasma electrons to the
cathode sputtering area and generates positive plasma potential.
The positive plasma potential accelerates gas and sputtered target
material ions from the cathode sputtering target area towards the
substrate that improves deposition rate and increases ion
bombardment on the substrate. The reverse electron current during
positive voltage can be up to 50% from the discharge current during
negative voltage.
[0032] In some embodiments, the magnetically enhanced sputtering
source is a hollow cathode magnetron. The hollow cathode magnetron
includes a hollow cathode sputtering target and a second tunable
PFN or PCN, which has a plurality of capacitors and inductors. The
resonance mode associated with the second tunable PFN or PCN is a
function of the input unipolar voltage pulse amplitude, duration,
and frequency generated by the high-power pulse power supply,
inductance, resistance and capacitance of the hollow cathode
magnetron or any other magnetically enhanced device, the
inductance, capacitance, and resistance of the cables between the
second tunable PFN or PCN and hollow cathode magnetron, and a
plasma impedance of the hollow cathode magnetron sputtering source
itself as well as the sputtered target material.
[0033] In some embodiments, rather than the hollow cathode
magnetron, a cylindrical magnetron is connected to an output of the
tunable PFN or PCN. In some embodiments, rather than the hollow
cathode magnetron, a magnetron with flat target is connected to the
output of the second tunable PFN or PCN. In the resonance mode, the
output negative voltage amplitude of the high-power pulse voltage
mode asymmetrical AC waveform on the magnetically enhanced device
exceeds the negative voltage amplitude of the input unipolar
voltage pulses into the second tunable PFN or PCN by 1.1-5 times.
The unipolar negative high-power voltage output can be in the range
of 400V-5000V. In the resonance mode, the absolute value of the
negative voltage amplitude of the asymmetrical AC waveform can be
in the range of 750-10000 V. In the resonance mode, the output
positive voltage amplitude of the asymmetrical AC waveform can be
in the range of 100-5000 V. In some cases, the resonance mode of
the negative voltage amplitude of the output AC voltage waveform
can reach a maximum absolute value while holding all other
component parameters (such as the pulse generator output, PFN or
PCN values, cables and HEDP source) constant, wherein a further
increase of the input voltage to the second tunable PFN or PCN does
not result in a voltage amplitude increase on the HEDP source, but
rather an increase in the duration of the negative pulse in the
asymmetric AC voltage waveform on the HEDP source.
[0034] Sputtering processes are performed with a magnetically and
electrically enhanced HEDP plasma source positioned in a vacuum
chamber. As mentioned above, the plasma source can be any
magnetically enhanced sputtering source with a different shape of
sputtering cathode target. Magnetic enhancement can be performed
with electromagnets, permanent magnets, stationary magnets,
moveable magnets, and/or rotatable magnets. In the case of a
magnetron sputtering source, the magnetic field can be balanced or
unbalanced. A typical pulse power density of the HEDP sputtering
process during a negative portion of the high voltage AC waveform
is in the range of 0.1-20 kW/cm.sup.2. A typical pulse discharge
current density of the HEDP sputtering process during a negative
portion of the high voltage AC waveform is in the range of 0.1-20
A/cm.sup.2. In the case of the hollow cathode magnetron sputtering
source, the magnetic field lines form a magnetron configuration on
a bottom surface of the hollow cathode target from the hollow
cathode magnetron. Magnetic field lines are substantially parallel
to the bottom surface of the hollow cathode target and partially
terminate on the bottom surface and side walls of the hollow
cathode target. The height of the side walls can be in the range of
5-100 mm. Due to the presence of side walls on the hollow cathode
target, electron confinement is significantly improved when
compared with a flat target in accordance with the disclosed
embodiments. In some embodiments, an additional magnet assembly is
positioned around the walls of the hollow cathode target. In some
embodiments, there is a magnetic coupling between additional
magnets and a magnetic field forms a magnetron configuration.
[0035] Since the high-power resonance asymmetric AC voltage
waveform can generate HEDP plasma and, therefore, significant power
on the magnetically enhanced sputtering source, the high-power
resonance asymmetric AC voltage waveform is pulsed in programmable
bursts to prevent damage to the magnetically enhanced sputtering
source from excess average power. The programmable duration of the
high-power resonance asymmetric AC voltage waveforms pulse bursts
can be in the range of 0.1-100 ms. The frequency of the
programmable high-power resonance asymmetric AC voltage waveforms
pulse bursts can be in the range of 1 Hz-10000 Hz. In some
embodiments, the high-power resonance asymmetric AC voltage
waveform is continuous or has a 100% duty cycle assuming the HEDP
plasma source can handle the average power. The frequency of the
pulsed high-power resonance asymmetric AC voltage waveform inside
the programmable pulse bursts can be programmed in the range of 100
Hz-400 kHz with a single frequency or mixed frequency.
[0036] The magnetically enhanced HEDP sputtering source includes a
magnetron with a sputtering cathode target, an anode, a magnet
assembly, a regulated voltage source connected to a high-power
pulsed DC power supply with a built in first pulse forming network
to control voltage rise-time and or fall time of the unipolar
negative pulse with programmable output pulse voltage amplitude,
frequency, and duration. The pulsed power supply is connected to
the input of the second tunable PFN or PCN, and the output of the
second tunable PFN or PCN is connected to the sputtering cathode
target on the magnetically enhanced sputtering source. The second
tunable PFN or PCN, in resonance mode, generates the high-power
resonance asymmetrical AC voltage waveforms and provides HEDP
discharge on the magnetically enhanced sputtering source.
[0037] The magnetically enhanced high-power pulse resonance
asymmetric AC HEDP sputtering source may include a hollow cathode
magnetron with a hollow cathode sputtering target, a second magnet
assembly positioned around the side walls of the hollow cathode
target, an electrical switch positioned between the second tunable
PFN or PCN and hollow cathode magnetron with a flat sputtering
target rather than a hollow cathode shape, and a magnetic array
with permanent magnets, electromagnets, or a combination
thereof.
[0038] The magnetically enhanced high-power pulse resonance
asymmetric AC HEDP sputtering apparatus includes a magnetically
enhanced HEDP sputtering source, a vacuum chamber, a substrate
holder, a substrate, a feed gas mass flow controller, and a vacuum
pump.
[0039] The magnetically enhanced high-power pulse resonance
asymmetric AC HEDP sputtering apparatus may include one or more
electrically and magnetically enhanced HEDP sputtering sources,
substrate heater, controller, computer, high-density plasma radio
frequency (RF) gas activation source mounted remotely or as a ring
source between the HEDP source and the substrate or around the
substrate, substrate bias power supply, matching network,
electrical switch positioned between the second tunable PFN or PCN
and magnetically enhanced HEDP sputtering source, and a plurality
of electrical switches connected with a plurality of magnetically
enhanced high-power pulse resonance asymmetric AC HEDP sputtering
sources and output of the second tunable PFN or PCN.
[0040] A method of providing high-power pulse resonance asymmetric
AC HEDP film sputtering includes positioning a magnetically
enhanced sputtering source inside a vacuum chamber, connecting the
cathode target to the output of the second tunable PFN or PCN that,
in resonance mode, generating the high-power asymmetrical AC
waveform, positioning a substrate on a substrate holder, providing
feed gas, programing voltage pulses frequency and duration,
adjusting pulse voltage amplitude of the programmed voltage pulses
with fixed frequency and duration feeding the second tunable PFN or
PCN, generating the output high voltage asymmetrical AC waveform
with a negative voltage amplitude that exceeds the negative voltage
amplitude of the negative unipolar voltage pulses in the resonance
mode, thereby resulting in a high-power pulse resonance asymmetric
AC HEDP discharge.
[0041] The method of magnetically enhanced high-power pulse
resonance asymmetric AC HEDP film sputtering may include
positioning an electrical switch between the hollow cathode
magnetron and the second tunable PFN or PCN that, in resonance
mode, generates the high voltage asymmetrical AC waveform, applying
heat to the substrate or cooling down the substrate, applying
direct current (DC) or radio frequency (RF) continuously and/or
using a pulse bias voltage to the substrate holder to generate a
substrate bias, connecting the second tunable PFN or PCN that, in
resonance mode, generates the high voltage asymmetrical AC waveform
simultaneously to the plurality of hollow cathode magnetrons or
magnetrons with flat targets, and igniting and sustaining
simultaneously HEDP in the plurality of the hollow cathode
magnetron.
[0042] The disclosed embodiments include a method of sputtering a
layer on a substrate using a high-power pulse resonance asymmetric
AC HEDP magnetron. The method includes configuring an anode and a
cathode target magnet assembly to be positioned in a vacuum chamber
with a sputtering cathode target and the substrate, applying
high-power negative unipolar voltage pulses with regulated
amplitude and programmable duration and frequency to a second
tunable PFN or PCN, wherein the second tunable PFN or PCN includes
a plurality of inductors and capacitors, and adjusting an amplitude
associated with the unipolar voltage pulses with programmed
duration and frequency to cause a resonance mode associated with
the second tunable pulse forming network to produce an output
high-power pulse resonance asymmetric AC on the HEDP sputtering
source. The output high-power pulse resonance asymmetric AC voltage
waveform from the second tunable PFN or PCN is operatively coupled
to the HEDP sputtering cathode target, and the output high-power
pulse resonance asymmetric AC voltage waveform includes a negative
voltage exceeding or equal to the amplitude of the input unipolar
voltage pulses coming to the second tunable PFN or PCN during the
resonance mode and sputtering discharge of the HEDP magnetron. In
some cases, with all conditions fixed, any further increase of the
amplitude of the unipolar voltage pulses causes only an increase in
the duration of the maximum value of the negative voltage amplitude
of the output high-power asymmetric AC voltage waveform in response
to the pulse forming network being in the resonance mode, thereby
causing the HEDP magnetron sputtering discharge to form the layer
on the substrate.
[0043] The disclosed embodiments further include an apparatus that
sputters a layer on a substrate using a high-power pulse resonance
asymmetric AC HEDP magnetron. The apparatus includes an anode,
cathode target magnet assembly, regulated high voltage source with
variable power, high-power pulse power supply with programmable
voltage pulse duration and frequency power supply, and a second
tunable PFN or PCN. The anode and cathode target magnet assembly
are configured to be positioned in a vacuum chamber with a
sputtering cathode target and the substrate. The high-power pulse
power supply with a built-in first PFN generates programmable
unipolar negative voltage DC pulses with defined amplitude,
frequency, and duration. The second tunable PFN or PCN includes a
plurality of inductors and capacitors, and the amplitude of the
voltage pulses are adjusted to be in the resonance mode associated
with the second tunable PFN or PCN and magnetically enhanced
sputtering source for specific programmed pulse parameters, such as
amplitude, frequency and duration of the unipolar voltage pulses.
The output of the second tunable PFN or PCN is operatively coupled
to the sputtering cathode target, and the output of the second
tunable PFN or PCN in the resonance mode generates a high-power
resonance asymmetric AC voltage waveform that includes a negative
voltage exceeding the amplitude of the input to second tunable PFN
or PCN unipolar voltage pulses. An AC voltage waveform sustains
plasma and forms high-power pulse resonance asymmetric AC HEDP
magnetron sputtering discharge, thereby causing the HEDP magnetron
sputtering discharge to form the layer of the sputtered target
material on the substrate.
[0044] The disclosed embodiments also include a computer-readable
medium storing instructions that, when executed by a processing
device, perform a method of sputtering a layer on a substrate using
a high energy density plasma (HEDP) magnetron, wherein the
operations include configuring an anode and a cathode target magnet
assembly to be positioned in a vacuum chamber with a sputtering
cathode target and the substrate, applying regulated amplitude
unipolar voltage pulses with programmed frequency and duration to
the second tunable PFN or PCN, wherein the pulse forming network
includes a plurality of inductors and capacitors, and adjusting a
pulse voltage for programmed voltage pulses frequency and duration
to cause a resonance mode associated with the second tunable PFN or
PCN. The output asymmetric AC voltage waveform is operatively
coupled to the sputtering cathode target, and the output asymmetric
AC voltage waveform includes a negative voltage exceeding the
amplitude of the regulated unipolar voltage pulses amplitude with
programmed frequency and duration during sputtering discharge of
the HEDP magnetron. A further increase in the amplitude of the
regulated unipolar voltage pulses with programmed frequency and
duration causes a constant amplitude of the negative voltage of the
output AC waveform in response to the pulse forming network being
in the resonance mode, thereby causing the HEDP magnetron
sputtering discharge to form the layer on the substrate.
[0045] Other embodiments will become apparent from the following
detailed description considered in conjunction with the
accompanying drawings. It is to be understood, however, that the
drawings are designed as an illustration only and not as a
definition of the limits of any of the embodiments.
BRIEF DESCRIPTION OF THE DRAWINGS
[0046] The following drawings are provided by way of example only
and without limitation, wherein like reference numerals (when used)
indicate corresponding elements throughout the several views, and
wherein:
[0047] FIG. 1 (a) shows an illustrative view of a train of output
negative unipolar voltage pulses with amplitude V1 and frequency f1
from a high-power pulse supply with programmable pulse voltage
duration and pulse voltage frequency;
[0048] FIG. 1 (b) shows an illustrative view of an output resonance
asymmetrical AC voltage waveform with a duration of negative
voltage .tau.1 from a second tunable pulse forming network (PFN) or
pulse converting network (PCN);
[0049] FIG. 1 (c) shows an illustrative view of a train of output
negative unipolar voltage pulses with amplitude V2 and frequency f1
from a high-power pulse supply with programmable pulse voltage
duration and pulse voltage frequency;
[0050] FIG. 1 (d) shows an illustrative view of the output
resonance asymmetrical AC voltage waveform with a duration of
negative voltage .tau.2 from the second tunable PFN or PCN;
[0051] FIG. 1 (e) shows an illustrative view of the output
resonance asymmetrical AC voltage waveform with three oscillations
from the second tunable PFN or PCN;
[0052] FIG. 1 (f) shows an illustrative view of the output
resonance asymmetrical AC current waveform with three oscillations
from the second tunable PFN or PCN;
[0053] FIG. 1 (g) shows an illustrative cross-sectional view of
components and magnetic field lines of a magnetically enhanced HEDP
sputtering source with a stationary cathode target magnetic
array;
[0054] FIG. 1 (h) shows an illustrative cross-sectional view of a
hollow cathode target;
[0055] FIG. 2 (a) shows an illustrative circuit diagram of the
high-power pulse supply connect to a second PFN or PCN to form a
resonance AC power supply connected to an HEDP source;
[0056] FIG. 2 (b) shows an illustrative view of a train of unipolar
voltage pulses with frequency f1 and amplitude V1 applied to the
second tunable PFN or PCN, and an output voltage waveform from the
second tunable PFN or PCN in-non-resonance mode in the second
tunable PFN or PCN;
[0057] FIG. 2 (c) shows an illustrative view of a train of unipolar
voltage pulses with frequency f2 and amplitude V2 applied to the
second tunable PFN or PCN, and an output voltage waveform from the
second tunable PFN or PCN in a partial pulsed DC modulated
non-resonance mode;
[0058] FIG. 2 (d) shows an illustrative view of a train of unipolar
voltage pulses with frequency f3 and amplitude V4 applied to the
second tunable PFN or PCN, and an output resonance asymmetrical AC
voltage waveform from the second tunable PFN or PCN in the
resonance mode.
[0059] FIG. 2 (e) shows an illustrative circuit diagram of the
second tunable PFN or PCN when the plurality of inductors and
capacitors are connected in series;
[0060] FIG. 2 (f) shows an illustrative circuit diagram of the
second tunable PFN or PCN when inductors and capacitors are
connected in parallel;
[0061] FIG. 3 (a) shows an illustrative view of a train of input
unipolar negative voltage pulses with two different voltage
amplitudes applied to the second tunable PFN or PCN.
[0062] FIG. 3 (b) shows an illustrative view of output resonance
asymmetrical AC voltage waveform pulses with two different voltage
amplitudes generated at resonance conditions in the second tunable
PFN or PCN;
[0063] FIG. 4(a) shows an illustrative circuit diagram of the
second tunable PFN or PCN and a plurality of electrical
switches;
[0064] FIG. 4 (b) shows a train of resonance asymmetrical AC
waveforms applied to different magnetically enhanced sputtering
sources;
[0065] FIG. 5 (a) shows an illustrative view of the magnetically
enhanced HEDP sputtering apparatus;
[0066] FIG. 5 (b) shows different voltage pulse shapes that can be
generated by a substrate bias power supply;
[0067] FIG. 5 (c) shows an illustrative view of a via in the
semiconductor wafer;
[0068] FIG. 6 (a) shows a train of resonance asymmetrical AC
voltage waveforms;
[0069] FIG. 6 (b) shows a plurality of unipolar voltage pulses
generated by a pulse DC power supply;
[0070] FIG. 6 (c) shows a plurality of unipolar RF voltage pulses
generated by a pulse RF power supply;
[0071] FIG. 7 shows a block diagram of at least a portion of an
exemplary machine in the form of a computing system that performs
methods according to one or more embodiments disclosed herein;
[0072] FIG. 8 (a) shows an illustrative circuit diagram of a
high-power resonance pulse forming network (PFN) or pulse
converting network (PCN) coupled to a high-frequency unipolar pulse
generator;
[0073] FIG. 8 (b) shows illustrative views of trains of oscillatory
unipolar voltage pulses applied to the second tunable PFN or PCN,
and an output voltage waveform from the second tunable PFN or PCN
without a resonance mode in the second tunable PFN or PCN;
[0074] FIGS. 8 (c, d) show illustrative views of trains of
oscillatory unipolar voltage pulses applied to the second tunable
PFN or PCN, and an output voltage waveform from the second tunable
PFN or PCN with a resonance mode in the second tunable PFN or
PCN;
[0075] FIGS. 9 (a, b) show a hollow cathode target combined from
two pieces;
[0076] FIG. 10 (a) shows a hollow cathode target combined from two
pieces and connected to two different power supplies;
[0077] FIG. 10 (b) shows the voltage output from two high-power
pulse resonance AC power supplies;
[0078] FIG. 11 shows an illustrative circuit diagram of the
high-power resonance pulse forming network (PFN) or PCN including a
transformer and diodes;
[0079] FIGS. 12 (a)-(g) show different AC voltage waveforms;
[0080] FIG. 13 shows arc resonance AC discharge current and arc
resonance AC discharge voltage waveforms;
[0081] FIGS. 14 (a, b) show output voltage waveforms from the
high-power resonance pulse forming network (PFN) when connected to
the HEDP magnetron and generating HEDP discharge;
[0082] FIG. 15 (a) shows an illustrative circuit diagram of the
high-power pulse generator with built-in PFN connected to a second
tunable PFN or pulse converter network (PCN), which is connected to
an HEDP magnetron source producing a pulsed resonance AC discharge
to form a thin film layer on a substrate;
[0083] FIG. 15 (b) shows an illustrative view of a train of input
unipolar negative voltage pulses with two different voltage
amplitudes applied to the tunable PCN;
[0084] FIG. 15 (c) shows an illustrative view of output resonance
asymmetrical AC voltage waveform pulses with two different voltage
amplitudes generated at resonance conditions in the tunable
PCN;
[0085] FIG. 15 (d) shows an illustrative view of a train of input
oscillatory unipolar negative voltage pulses with two different
voltage amplitudes and controlled voltage rise-time and fall-time
applied to the tunable PCN;
[0086] FIG. 15 (e) shows an illustrative view of output resonance
asymmetrical AC voltage waveform pulses with two different voltage
amplitudes generated at resonance conditions in the tunable
PCN;
[0087] FIG. 15 (f) shows an illustrative view of a train of
unipolar voltage pulses with frequency B5 and amplitude V1 applied
to the tunable PCN, and an output voltage waveform from the tunable
PCN in non-resonance mode in the tunable PCN;
[0088] FIG. 15 (g) shows an illustrative view of a train of
unipolar voltage pulses with frequency B6 and amplitude V2 applied
to the tunable PCN, and an output voltage waveform from the tunable
PCN in a modulated non-resonance mode;
[0089] FIG. 15 (h) shows an illustrative view of a train of
unipolar voltage pulses with frequency B7 and amplitude V4 applied
to the tunable PCN, and an output resonance asymmetrical AC voltage
waveform from the tunable PCN in the resonance mode;
[0090] FIG. 15 (i) shows an illustrative view of a train of
oscillatory unipolar voltage pulses with frequency B8 and amplitude
V1 and controlled voltage rise-time and fall-time applied to the
tunable PCN, and an output voltage waveform from the tunable PCN in
non-resonance mode in the tunable PCN;
[0091] FIG. 15 (j) shows an illustrative view of a train of
oscillatory unipolar voltage pulses with frequency B9 and amplitude
V2 and controlled voltage rise-time and fall-time applied to the
tunable PCN, and an output voltage waveform from the tunable PCN in
a modulated non-resonance mode;
[0092] FIG. 15 (k) shows an illustrative view of a train of an
oscillatory unipolar voltage pulses with frequency B10 and
amplitude V4 and controlled voltage rise-time and fall-time applied
to the tunable PCN, and an output resonance asymmetrical AC voltage
waveform from the tunable PCN in the resonance mode;
[0093] FIG. 15 (l) shows an illustrative view of a train of input
unipolar negative voltage pulses with two different voltage
amplitudes applied to the tunable PCN with burst time of B11 and
two different frequencies B12 and B13;
[0094] FIG. 15 (m) shows an illustrative view of mixed output
unipolar voltage pulses and resonance asymmetrical AC voltage
waveform pulses with two different voltage amplitudes generated in
the tunable PCN;
[0095] FIG. 16 (a) shows an illustrative cross-sectional view of
components and magnetic field lines of a magnetically enhanced HEDP
sputtering source with a stationary cathode target magnetic array
connected to the tunable PCN and high pulse power generator with
built-in PFN;
[0096] FIG. 16 (b) shows an illustrative cross-sectional view of a
hollow cathode target;
[0097] FIG. 17 (a) shows an illustrative cross-sectional view of
components and magnetic field lines of a magnetically enhanced HEDP
sputtering source with a stationary cathode target magnetic array
connected to the tunable PCN and high pulse power generator with
built-in PFN;
[0098] FIG. 17 (b) shows an illustrative cross-sectional view of a
shaped geometry hollow cathode target that enhances the ionization
process;
[0099] FIG. 18 (a) shows an illustrative cross-sectional view of
components and magnetic field lines of a magnetically enhanced HEDP
sputtering source with a stationary cathode target magnetic array
connected to a high frequency generator, the tunable PCN, and high
pulse power generator with built-in PFN;
[0100] FIG. 18 (b) shows an illustrative cross-sectional view of a
hollow cathode target;
[0101] FIG. 19 (a) shows an illustrative view of the magnetically
enhanced HEDP sputtering apparatus with a ring HDP radio frequency
(RF) gas source positioned between the HEDP source and the
substrate;
[0102] FIG. 19 (b) shows different voltage pulse shapes that can be
generated by a substrate bias power supply;
[0103] FIG. 20 (a) shows an illustrative view of sputtering
apparatus equipped with multiple magnetically enhanced HEDP
sources;
[0104] FIG. 20 (b) shows different voltage pulse shapes that can be
generated by a substrate bias power supply;
[0105] FIG. 20 (c) shows different voltage pulse shapes that can be
generated by a substrate bias power supply;
[0106] FIG. 21 (a) shows an illustrative view of the magnetically
enhanced HEDP sputtering apparatus with a remote HDP RF gas source
positioned on a side of a chamber; and
[0107] FIG. 21 (b) shows different voltage pulse shapes that can be
generated by a substrate bias power supply.
[0108] FIG. 22 (a) shows an illustrative cross-sectional view of an
embodiment of a magnetically enhanced chemical vapor deposition
(CVD) source;
[0109] FIG. 22 (b) shows an illustrative cross-sectional view of an
embodiment of the magnetic field lines for the magnetically
enhanced CVD source;
[0110] FIG. 22 (c) shows a timing diagram of negative voltage
pulses that can be generated by a pulsed power supply and applied
to the pole piece from the magnetically enhanced CVD source;
[0111] FIG. 22 (d) shows a timing diagram of negative RF voltage
applied to the cathode target when negative pulses are applied to
the pole piece from the magnetically enhanced CVD source;
[0112] FIG. 22 (e) shows a timing diagram of negative voltage
pulses with different amplitudes that can be generated by a pulsed
power supply and applied to the pole piece from the magnetically
enhanced CVD source;
[0113] FIG. 22 (f) shows a timing diagram of negative RF voltage
applied to the cathode target when negative voltage pulses with
different amplitudes are applied to the pole piece from the
magnetically enhanced CVD source;
[0114] FIG. 22 (g) shows a timing diagram of negative voltage
pulses with different frequencies that can be generated by a pulsed
power supply and applied to the pole piece from the magnetically
enhanced CVD source;
[0115] FIG. 22 (h) shows a timing diagram of negative RF voltage
applied to the cathode target when negative voltage pulses with
different frequencies are applied to the pole piece from the
magnetically enhanced CVD source;
[0116] FIG. 22 (i) shows a timing diagram of negative voltage
pulses that can be generated by a pulsed power supply and applied
to the pole piece from the magnetically enhanced CVD source;
[0117] FIG. 22 (j) shows a timing diagram of negative RF voltage
applied to an inductively grounded cathode target when negative
voltage pulses with different frequencies are applied to the pole
piece from the magnetically enhanced CVD source;
[0118] FIG. 23 (a) shows an illustrative cross-sectional view of an
embodiment of the magnetically enhanced CVD source.
[0119] FIG. 23 (b) shows an illustrative cross-sectional view of a
gap between the cathode and the anode of the magnetically enhanced
CVD source with a pole piece made from non-magnetic material;
[0120] FIG. 23 (c) shows an illustrative cross-sectional view of a
gap between the cathode and the anode of the magnetically enhanced
CVD source when magnets that form cusp magnetic field are
electromagnets;
[0121] FIG. 24 shows a timing diagram of negative voltage pulses
that can be generated by a pulsed power supply and applied to the
pole piece;
[0122] FIG. 25 (a, b, c, d) show timing diagrams of the negative
voltage pulses that can be generated by a pulsed power supply and
applied to the cathode assembly;
[0123] FIG. 26 (a, b, c, d) show timing diagrams of RF voltages
that can be applied to the cathode assembly;
[0124] FIG. 27 (a, b, c, d, e) show timing diagrams of different
shapes of voltage pulses that can be applied to the cathode
assembly;
[0125] FIG. 28 shows an illustrative cross-sectional view of an
embodiment of the magnetically enhanced CVD apparatus for thin film
deposition on a round substrate, such as a Si substrate;
[0126] FIG. 29 shows an illustrative cross-sectional view of an
embodiment of the magnetically enhanced CVD system including two
rectangular CVD sources;
[0127] FIG. 30 shows an illustrative cross-sectional view of an
embodiment of the magnetically enhanced CVD source and processes
for applying a coating on a razor blade tip;
[0128] FIG. 31 shows an illustrative cross-sectional view of an
embodiment of a magnetically enhanced chemical vapor deposition
(CVD) source with a shield separating the gap from the magnetic
pole pieces, an accelerating grid, a hollow cathode magnet assembly
with a field perpendicular to the hollow cathode target and
coupling with the cusp field, multiple RF power supplies, and a
high-power pulsed power supply connected to the hollow cathode
target, and inductor connected to a switch;
[0129] FIG. 32 shows an illustrative cross-sectional view of an
embodiment of a magnetically enhanced chemical vapor deposition
(CVD) source with a shield separating the gap from the magnetic
pole pieces, an accelerating grid, multiple RF power supplies
connected to the hollow cathode target, and an inductor connected
to the switch;
[0130] FIG. 33 shows an illustrative cross-sectional view of an
embodiment of a magnetically enhanced chemical vapor deposition
(CVD) source with a shield separating the gap from the magnetic
pole pieces, an accelerating grid, multiple RF power supplies
connected to the hollow cathode target, an inductor connected to a
switch, a hollow cathode with a specific magnet assembly forming an
outer ring coupling to the cusp field through the gap and an inner
magnet assembly forming a magnetron configuration on the hollow
cathode target;
[0131] FIG. 34 shows an illustrative cross-sectional view of an
embodiment of a magnetically enhanced chemical vapor deposition
(CVD) source with a shield separating the gap from the magnetic
pole pieces, an accelerating grid, multiple RF power supplies and a
high power pulsed power supply connected to a hollow cathode
target, an inductor connected to a switch, the hollow cathode
including a specific magnet assembly forming an outer ring coupling
to the cusp field through the gap and an inner magnet assembly
forming a magnetron configuration on the hollow cathode target;
[0132] FIG. 35 shows an illustrative cross-sectional view of an
embodiment of a magnetically enhanced chemical vapor deposition
(CVD) source with a shield separating the gap from the magnetic
pole pieces, an accelerating grid, a high power pulsed power supply
connected to the hollow cathode target, an inductor connected to a
switch, the hollow cathode including a specific magnet assembly
forming an outer ring coupling to the cusp field through the gap
and an inner magnet assembly forming a magnetron configuration on
the hollow cathode target;
[0133] FIG. 36 shows an illustrative cross-sectional view of an
embodiment of a magnetically enhanced chemical vapor deposition
(CVD) source with a shield separating the gap from the magnetic
pole pieces, an accelerating grid, a hollow cathode magnet assembly
with a field perpendicular to the hollow cathode target and
coupling with the cusp field, a high power pulsed power supply
connected to the hollow cathode target, and an inductor connected
to a switch;
[0134] FIG. 37 shows timing diagrams of two RF voltages running in
two different modes, one being continuous, and the second RF
voltage being pulsed with varying pulsed power that can be applied
to the magnetically enhanced chemical vapor deposition (CVD)
cathode assembly;
[0135] FIG. 38 shows timing diagrams of two RF voltages running in
two different modes, one being continuous, and the second RF
voltages being pulsed with the same pulsed power that can be
applied to the magnetically enhanced chemical vapor deposition
(CVD) cathode assembly;
[0136] FIG. 39 show timing diagrams of two RF voltages running in
pulsed mode with two different voltage levels superimposed with a
varying high-power asymmetric AC pulse that can be applied to the
magnetically enhanced chemical vapor deposition (CVD) cathode
assembly;
[0137] FIG. 40 shows a timing diagram of pulsed RF voltages that
can be applied to the magnetically enhanced chemical vapor
deposition (CVD) cathode assembly;
[0138] FIG. 41 shows a timing diagram of two synchronized pulsed RF
voltages in two different power settings that can be applied to the
magnetically enhanced chemical vapor deposition (CVD) cathode
assembly;
[0139] FIG. 42 shows a timing diagram of two RF voltages running in
pulsed mode with two different voltage levels, super-imposed with a
high power asymmetric AC pulse that can be applied to the
magnetically enhanced chemical vapor deposition (CVD) cathode
assembly.
[0140] FIG. 43 shows timing diagrams of two RF phase locked
voltages having the same frequency in continuous mode with two
different power levels that can be applied to the magnetically
enhanced chemical vapor deposition (CVD) cathode assembly;
[0141] FIG. 44 shows a timing diagram of a high power asymmetric AC
pulse that can be applied to the magnetically enhanced chemical
vapor deposition (CVD) cathode assembly;
[0142] FIG. 45 shows a timing diagram of a high power asymmetric AC
pulse with voltage peaks that can be applied to the magnetically
enhanced chemical vapor deposition (CVD) cathode assembly;
[0143] FIG. 46 shows timing diagrams of two RF voltages in pulsed
mode with two different voltage levels superimposed with a varying
high power asymmetric AC pulse single voltage peak and double peak
that can be applied to the magnetically enhanced chemical vapor
deposition (CVD) cathode assembly;
[0144] FIG. 47 (a) shows timing diagrams of unipolar voltage pulses
provided to a tunable PCN connected to the magnetically enhanced
chemical vapor deposition (CVD) cathode assembly producing a
high-power DC pulse that can be applied to the magnetically
enhanced chemical vapor deposition (CVD) cathode assembly;
[0145] FIG. 47 (b) shows timing diagrams of unipolar voltage pulses
provided to a tunable PCN connected to the magnetically enhanced
chemical vapor deposition (CVD) cathode assembly producing a
high-power DC pulse with oscillations that can be applied to the
magnetically enhanced chemical vapor deposition (CVD) cathode
assembly;
[0146] FIG. 47 (c) shows timing diagrams of unipolar voltage pulses
provided to a tunable PCN connected to the magnetically enhanced
chemical vapor deposition (CVD) cathode assembly producing a
high-power resonance asymmetric or symmetric AC pulse that can be
applied to the magnetically enhanced chemical vapor deposition
(CVD) cathode assembly;
[0147] FIG. 48(a) shows an illustrative diagram of a high-power
pulsed voltage power supply connected to the tunable PCN converting
the unipolar pulsed DC pulses to a resonance asymmetric pulsed AC
discharge when connected to a magnetically enhanced chemical vapor
deposition (CVD) source;
[0148] FIG. 48 (b) show a timing diagram of a two-voltage level
high power unipolar pulsed DC pulses powering the tunable PCN;
and
[0149] FIG. 48 (c) shows a timing diagram at the output of the
tunable PCN with two voltage levels and high-power resonance
asymmetric AC pulses provided to a magnetically enhanced chemical
vapor deposition (CVD) source.
[0150] It is to be appreciated that elements in the figures are
illustrated for simplicity and clarity. Common but well-understood
elements that are useful or necessary in a commercially feasible
embodiment are not shown in order to facilitate a less hindered
view of the illustrated embodiments.
DETAILED DESCRIPTION
[0151] A high energy density plasma (HEDP) magnetically enhanced
sputtering source includes a hollow cathode magnetron, pulse power
supply, and second tunable pulse forming network (PFN) or pulse
converting network (PCN). The second tunable PFN or PCN, in
resonance mode, generates a high voltage asymmetrical alternating
current (AC) waveform with a frequency in the range of 400 Hz to
400 kHz. The resonance mode of the second tunable PFN or PCN, as
used herein, is a mode in which input negative unipolar voltage
pulses with adjusted amplitude, and programmed duration, and
frequency generate an output high-power resonance pulse asymmetric
AC voltage waveform with a negative amplitude that exceeds or is
equal to the negative amplitude of the input negative unipolar
voltage pulses. In some cases, further increase of the amplitude of
the input negative unipolar voltage pulses from the high-power
pulse power supply does not increases the negative amplitude of the
output high resonance asymmetric AC voltage waveform, but increases
the duration of the maximum value of the negative resonance AC
voltage waveform as shown in FIGS. 1 (a, b, c, d). In some, a
further increase of the amplitude of the input negative unipolar
voltage pulses from the high-power pulse power supply increases the
negative amplitude of the output high resonance asymmetric AC
voltage waveform. When the amplitude of the input unipolar negative
DC voltage pulses equals V1 as shown in FIG. 1 (a) at the output of
the second tunable PFN or PCN during the HEDP discharge, there is
an asymmetrical resonance AC voltage waveform as shown in FIG. 1
(b). The resonance asymmetrical AC voltage waveform has a negative
portion V.sup.- with a duration .tau.1, and positive portions
V.sub.1.sup.+ and V.sub.2.sup.+. When the amplitude voltage becomes
V2 and V2>V1, the amplitude of the resonance negative AC voltage
waveform is the same as V3, but the duration is .tau.2 and
.tau.2>.tau.1. A negative portion of the resonance asymmetrical
AC voltage waveform generates AC discharge current I.sub.1, and
positive voltage generates a discharge current I.sub.2 as shown in
FIGS. 1 (e, f). A negative portion of the high-power asymmetrical
resonance AC voltage waveform generates HEDP magnetron discharge
from feed gas and sputtering target material atoms inside a hollow
cathode target due to high discharge voltage and improved electron
confinement. During the sputtering process, the hollow cathode
target power density is in the range of 0.1 to 20 kW/cm.sup.2. A
positive portion of the high voltage asymmetrical AC voltage
waveform provides absorption of electrons from the HEDP by the
hollow cathode magnetron surface and, therefore, generates a
positive plasma potential that causes ions to accelerate towards
the hollow cathode target walls and a substrate. The ion energy is
a function of the amplitude and duration of the positive voltage.
The duration of the maximum absolute value of the negative voltage
from the high voltage asymmetrical AC voltage waveform is in the
range of 0.001-to 100 ms. The discharge current during the positive
voltage of the asymmetrical resonance AC voltage waveform can be in
the range of 5-50% of the discharge current during the negative
voltage from the AC voltage waveform.
[0152] The high-power pulse resonance asymmetric AC HEDP magnetron
sputtering process is substantially different from high-power
impulse magnetron sputtering (HIPIMIS) due to the resonance AC
nature of the discharge generated by the second tunable PFN or PCN
and HEDP magnetron discharge. The high-power impulse magnetron
power supply (HIPMIS, HPPMS, or MPP) generates a unipolar negative
pulsed voltage DC output on the magnetron with defined pulse
parameters, such as amplitude, width, and frequency to form a layer
on a substrate. Adding a second pulse forming or converting network
in between the high-power pulse generator and the magnetron
converts the unipolar negative pulsed DC to a high-power pulsed
resonance asymmetric AC discharge to form a layer on a substrate.
The resonance asymmetrical high-power AC discharge is substantially
more stable when compared with HIPIMS discharge. In the resonance
mode, the high-power AC voltage waveform can be symmetrical or
asymmetrical. For example, for a carbon hollow cathode magnetron, a
sputtering process with a stable, high-power asymmetric AC
discharge current density of about 6 A/cm.sup.2 is obtained,
thereby forming a dense, smooth, and hard, low-stress diamond-like
carbon (DLC) layer on the substrate at low temperature. The
disclosed embodiments relate to ionized physical vapor deposition
(I-PVD) with an HEDP sputtering apparatus and method.
[0153] A sputtering process can be performed with a hollow cathode
magnetron sputtering source and direct current (DC) power supply.
An example of such an apparatus and sputtering process is described
in Zhehui Wang and Samuel A. Cohen, Hollow cathode magnetron, J.
Vac. Sci. Technol., Vol. 17, January/February 1999, which is
incorporated herein by reference in its entirety. However, these
techniques do not address the operation of a hollow cathode
magnetron sputtering source with a high voltage resonance
asymmetrical AC voltage waveform, a method of accelerating ions
from the feed gas and sputtering target material atoms by
controlling a positive voltage portion of a high-power asymmetrical
resonance AC voltage waveform applied to an entirely hollow cathode
magnetron, or operation of a pulse power supply and second tunable
PFN or PCN when the second tunable PFN or PCN is in a resonant mode
and generating a high-power resonance asymmetrical AC voltage
waveform on a hollow cathode magnetron sputtering source with power
pulse densities of about 1-20 kW/cm2.
[0154] A magnetically and electrically enhanced HEDP sputtering
source 100 shown in FIG. 1(g) includes a hollow cathode magnetron
101 and a high-power pulse resonance AC power supply 102, which
includes a high-power voltage source 119, a high-power pulsed power
supply with programmable voltage pulse frequency and amplitude 120,
and second tunable PFN or PCN 124. This second tunable PFN or PCN,
in resonance mode, generates a high-power resonance asymmetrical AC
waveform. The hollow cathode magnetron 101 includes a hollow
cathode target 103. The hollow cathode target 103 has side walls
104 and a bottom part 105 as shown in FIGS. 1 (g), (h). An anode
106 is positioned around the side walls 104. Magnets 107, 108, and
magnetic pole piece 109 are positioned inside a water jacket 110.
The water jacket 110 is positioned inside a housing 111. The hollow
cathode target 103 is bonded to a copper backing plate 112. Magnets
107, 108 and magnetic pole piece 109 generate magnetic field lines
113, 114 that terminate on the bottom part 105 and form a magnetron
configuration. Magnetic pole piece 109 is positioned on a supporter
190. Magnetic field lines 115, 116 terminate on the side walls 104.
Water jacket 110 has a water inlet 117 and a water outlet 118. The
water inlet 117 and water outlet 118 are isolated from housing 111
by isolators 121. Water jacket 110 and, therefore, hollow cathode
target 101 are connected to a high-power pulse resonance AC power
supply 102. The following chemical elements, or a combination of
any two or more of these elements, can be used as a cathode
material: B, C, Al, Si, P, S, Ga, Ge, As, Se, In, Sn, Sb, Te, I,
Tl, Pb, Bi, Sc, Ti, Cr, Mn, Fe, Co, Ni, Cu, Zn, Y, Zr, Nb, Mo, Tc,
Ru, Rh, Pd, Ag, Cd, Lu, Hf, Ta, W, Re, Os, Ir, Pt, Au, La, Ce, Pr,
Nd, Pm, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb, Be, Mg, Ca, Sr, and/or
Ba. A combination of these chemical elements with the gases
O.sub.2, N.sub.2, F, Cl, and/or H.sub.2 can also be used as the
cathode material.
[0155] The hollow cathode target magnetic array may have
electromagnets rather than permanent magnets. In some embodiments,
the electromagnets are positioned around the side walls 104 of the
hollow cathode target. These side electromagnets can balance and
unbalance the hollow cathode target magnetic array.
[0156] In some embodiments, the hollow cathode target, during the
sputtering process, has a temperature between 20 C and 1000 C. A
high target temperature in the range of 0.5-0.7 of the melting
target temperature increases the deposition rate since the
sputtering yield is a function of the temperature in this
temperature range. In some embodiments, a portion of the target
material atoms arriving on the substrate is evaporated from the
target surface. In some embodiments, the sputtering yield is
increased due to high target temperature during the pulsed
power.
[0157] The high-power pulse resonance AC power supply 102 includes
a regulated voltage source with variable power feeding 119, a
high-power pulsed power supply with programmable voltage pulse
frequency and amplitude 120 and a second tunable PFN or PCN 124 as
shown in FIG. 2 (a). A high-power pulsed power supply with
programmable voltage pulse frequency and amplitude 120 has a
computer 123 and controller 122. A regulated voltage source with
variable power feeding 119 supplies voltage in the range of
400-5000 V to the high-power pulsed power supply with programmable
voltage pulse frequency and amplitude 120. The high-power pulsed
power supply with programmable voltage pulse frequency and
amplitude 120 generates a train of unipolar negative voltage DC
pulses to the second tunable PFN or PCN 124. The amplitude of the
unipolar negative voltage pulses is in the range of 400 to 5000 V,
the duration of each of the voltage pulses is in the range of 1 to
100 .mu.s. The distance between voltages pulses can be in the range
of 0.4 to 1000 .mu.s, thus controlling the frequency to be between
0.1 to 400 kHz. In some embodiments, there is a step-up transformer
between the high-power pulsed power supply with programmable
voltage pulse frequency and amplitude 120 and the second tunable
PFN or PCN 124. In this case, the high-power pulsed power supply
with programmable voltage pulse frequency and amplitude 120
generates a train of AC voltage waveforms coming to the step-up
transformer. In some embodiments, there is a diode bridge between
the step-up transformer and second tunable PFN or PCN. The second
tunable PFN or PCN includes a plurality of specialized variable
inductors L1-L4 and a plurality of specialized variable capacitors
C1-C2 for high-power pulse applications. The value of the inductors
and capacitors can be controlled by computer 123 and/or controller
122. In some embodiments, at least one inductor and/or one
capacitor are variable and their values can be computer controlled.
The inductors L1, L2, L3, L4 values can be in the range of 0 to
1000 .mu.H each. Capacitors C1, C2, C3, and C4 have values in the
range of 0 to 1000 .mu.F each. The high-power pulse programmable
power supply 120 is connected to controller 122 and/or computer
123. Controller 122 and/or computer 123 control output values and
timing of the power supply 102. Power supply 102 can operate as a
standalone unit without connection to the controller 122 and/or
computer 123.
[0158] A high-power pulse resonance AC power supply 102 shown in
FIG. 2(a) includes output current and voltage monitors 125, 126,
respectively. The current and voltage monitors 125, 126 are
connected to an arc suppression circuit 127. If the current monitor
125 detects a high current and the voltage monitor 126 detects a
low voltage, the arc suppression circuit 127 is activated. It is to
be noted that the voltage monitor 126 is connected to an output of
the second tunable PFN or PCN. The arc suppression circuit sends a
signal to stop generating incoming voltage pulses to the second
tunable PFN or PCN 124 and connects the output of the second
tunable PFN or PCN through switch 131 to the positive electrical
potential generated by power supply 130 in order to eliminate
arcing as shown in FIG. 2 (a). The hollow cathode is shown as a
C-shaped structure coupled to the output of the second tunable PFN
or PCN 124.
[0159] The train of unipolar negative voltage DC pulses from the
high-power pulse programmable power supply 120 is provided to the
second tunable PFN or PCN 124. Depending on the amplitude,
duration, and frequency of the input unipolar negative voltage DC
pulses in the train, the output train from the second tunable PFN
or PCN 124 of the unipolar negative voltage DC pulses can have a
different shape and amplitude when compared with input unipolar
negative voltage DC pulses. In non-resonant mode, in the second
tunable PFN or PCN 124, the input train of unipolar negative
voltage DC pulses forms one negative voltage pulse with an
amplitude equivalent to the amplitude of the negative unipolar
voltage DC pulses and a duration equivalent to the duration of the
input train of unipolar negative voltage DC pulses. When connected
with the magnetically enhanced sputtering source, this voltage
pulse can generate a quasi-static pulse DC discharge as shown in
FIG. 2 (b). In partial resonance mode as shown in FIG. 2 (c), in
the second tunable PFN or PCN 124, the input train of negative
unipolar DC pulses forms one negative pulse with an amplitude and
duration, but with voltage oscillations. The amplitude of these
oscillations can be 30-80% of the total voltage amplitude. The
frequency of the voltage oscillations or modulations is
substantially equivalent to the frequency of the input unipolar
negative voltage DC pulses. This mode of operation is beneficial to
maintaining a high deposition rate, which is greater than that
obtained in full resonance mode, and a high ionization of sputtered
target material atoms. In resonance mode as shown in FIG. 2 (d),
the input train of unipolar negative voltage DC pulses forms
asymmetrical AC voltage waveforms with a maximum negative voltage
amplitude that can significantly exceed the voltage amplitude of
the input unipolar negative voltage DC pulses. In some embodiments,
in non-optimized resonance mode, the input train of unipolar
negative voltage DC pulses forms an asymmetrical AC voltage
waveform with a maximum negative voltage amplitude that does not
exceed negative voltage DC pulses. The positive amplitude of the AC
voltage waveform can reach the absolute value of the negative
amplitude and form a symmetrical AC voltage waveform. In FIG. 2
(b), the pulsing unit generates, during time t1, a train of
unipolar negative voltage DC pulses with a frequency f1 and
amplitude V1.
[0160] In FIG. 2 (c), the high-power pulse programmable power
supply 119 generates, during time t2, a train of unipolar negative
voltage DC pulses with a frequency f2 and amplitude V2. In this
case, the partial pulsed DC non-resonance mode exists. The
amplitude A of the voltage oscillations is about 30-80% of the
voltage amplitude V2. At the end of the pulse, the positive voltage
pulse 130 can be added by activating a positive voltage power
supply connected to the output of the second tunable PFN or PCN. If
the high-power pulse programmable power supply 120 generates
unipolar voltage pulses with a frequency f3 and amplitude V4 during
time t3, the resonance mode exists in the PFN 124 or PCN. The
resonance mode generates an asymmetrical AC voltage waveform. The
negative voltage amplitude V5 exceeds the amplitude of the input
voltage pulses V4 as shown in FIG. 2 (d). In some embodiments, the
amplitude of the voltage pulses V4 is -1200 V, the amplitude of the
negative voltage V5 is -1720 V. and the amplitude of the positive
voltage V6 is +280 V. In some embodiments, the amplitude of the
voltage pulses V4 is -1500 V, and amplitude of the negative voltage
V5 is -1720 V. The amplitude of the output positive voltage V6 is
+780 V. Different configurations of the second tunable PFN or PCN
that can be used to generate asymmetrical AC voltage waveforms are
shown in FIGS. 2 (e, f).
[0161] In some embodiments, the high-power pulse programmable power
supply pulsing 120 can generate a train of unipolar negative
voltage DC pulses with different amplitudes V7, V8, and frequencies
f4, f5 as shown in FIG. 3 (a). There is a resonance mode in the
second tunable PFN or PCN 124 when the output negative voltage
amplitudes V9, V10 exceed the amplitude of the input voltage pulses
V7, V8 as shown in FIG. 3 (b). During a negative portion of the
asymmetrical AC discharge, a surface of the hollow cathode target
103 emits secondary electrons due to ion bombardment, and during
the positive portion of the asymmetrical AC discharge, the hollow
cathode 103 absorbs electrons. The reduced amount of electrons in
the plasma generates a positive plasma potential. This plasma
potential accelerates ions towards the substrate.
[0162] During a reactive sputtering process, a positive electrical
charge is formed on the hollow cathode target surface 107 due to
reactive feed gas interaction with the hollow cathode target
surface 107. The positive voltage of the asymmetrical high voltage
AC waveform attracts electrons to the hollow cathode target
surface. These electrons discharge a positive charge on top of the
cathode target surface 107 and significantly reduce or completely
eliminate the probability of arcing. Since the electrons are
absorbed by the hollow cathode target surface 107, it is possible
to generate a positive space charge in the plasma. The positive
space charge provides additional energy to the ions in the plasma
and leads the ions toward the substrate and hollow cathode target
walls. The positive voltage applied to the cathode target surface
can attract negative ions that were formed when the negative
voltage was applied to the target surface and, therefore, reduce
substrate ion bombardment.
[0163] The second tunable PFN or PCN 124 can be connected with a
plurality of electrical switches 140-142. The switches 140, 141,
142 are connected to separate magnetron sputtering sources 150,
151, 152 as shown in FIG. 4 (a). For example, during operation, the
train 1 of pulses of high voltage AC waveform is directed to the
sputtering source 150, and the train 2 of pulses of high voltage AC
waveform is directed to the sputtering source 151 as shown in FIG.
4 (b). In this approach, small size sputtering sources can provide
large area sputtering.
[0164] The hollow cathode magnetron 101 from the magnetically and
electrically enhanced HEDP sputtering source 100 is mounted inside
a vacuum chamber 401 to construct the magnetically and electrically
enhanced HEDP sputtering apparatus 400 shown in FIG. 5 (a). The
vacuum chamber 401 contains feed gas and plasma and is coupled to
the ground. The vacuum chamber 401 is positioned in fluid
communication with a vacuum pump 402, which can evacuate the feed
gas from the vacuum chamber 401. Typical baseline pressure in the
vacuum chamber 401 is in a range of 10.sup.-6 to 10.sup.-9
Torr.
[0165] A feed gas is introduced into the vacuum chamber 401 through
a gas inlet 404 from feed gas sources. A mass flow controller 404
controls gas flow to the vacuum chamber 401. In an embodiment, the
vacuum chamber 401 has a plurality of gas inlets and mass flow
controllers. The gas flow is in a range of 1 to 100000 SCCM
depending on plasma operating conditions, pumping speed of a vacuum
pump 403, process conditions, and the like. Typical gas pressure in
the vacuum chamber 401 during a sputtering process is in a range of
0.5 to 50 mTorr. In some embodiments, a plurality of gas inlets and
a plurality of mass flow controllers sustain a desired gas pressure
during the sputtering process. The plurality of gas inlets and a
plurality of mass flow controllers may be positioned in the vacuum
chamber 401 at different locations. The feed gas can be a noble
gas, such as Ar, Ne, Kr, Xe; a reactive gas, such as N.sub.2,
O.sub.2; or any other gas suitable for sputtering or reactive
sputtering processes. The feed gas can also be a mixture of noble
and reactive gases.
[0166] The magnetically enhanced HEDP sputtering apparatus 400
includes a substrate support 408 that holds a substrate 407 or
other workpiece for plasma processing. The substrate support 408 is
electrically connected to a bias voltage power supply 409. The bias
voltage power supply 409 can include a radio frequency (RF) power
supply, alternating current (AC) power supply, very high frequency
(VHF) power supply, and/or direct current (DC) power supply. The
bias power supply 409 can operate in continuous mode or pulsed
mode. The bias power supply 409 can be a combination of different
power supplies that can provide different frequencies. The negative
bias voltage on the substrate is in a range of 0 to -2000 V. In
some embodiments, the bias power supply generates a pulse bias with
different voltage pulse frequency, amplitude, and shape, as shown
in FIG. 4 (b). In some embodiments, the voltage is a pulse voltage.
The negative substrate bias voltage can attract positive ions to
the substrate. The substrate support 408 can include a heater 414
that is connected to a temperature controller 421. The temperature
controller 421 regulates the temperature of the substrate 407. In
an embodiment, the temperature controller 420 controls the
temperature of the substrate 407 to be in a range of -100 C to
(+1000) C.
[0167] In some embodiments, the hollow cathode target material is
copper, and the substrate is a semiconductor wafer with at least
one via or trench. The semiconductor wafer diameter is in the range
of 25 to 450 mm. The depth of the via can be between 100 A and 400
.mu.m. The via can have an adhesion layer, barrier layer, and seed
layer. Typically, the seed layer is a copper layer. The copper
layer can be sputtered with the HEDP magnetron discharge as shown
in FIG. 5 (c).
[0168] A method of sputtering films, such as hard carbon, includes
the following conditions. The feed gas pressure can be in the range
of 0.5 to 50 mTorr. The substrate bias can be between 0 V and -120
V. The substrate bias voltage can be continuous or pulsed. The
frequency of the pulsed bias can be in the range of 1 Hz and 400
kHz. The substrate bias can be generated by the RF power supply and
matching network. The RF frequency can be in the range of 500 kHz
and 27 MHz. The RF bias can be continuous or pulsed. In an
embodiment, during the deposition, the substrate can have a
floating potential or be grounded. The high-power pulsed power
supply 120 generates a train of negative unipolar voltage pulses
with frequency and amplitude that provide a resonance mode in the
second tunable PFN or PCN 124. In this case, second tunable PFN or
PCN 124 generates the high voltage asymmetrical AC waveform and,
therefore, generates HEDP discharge. The negative AC voltage can be
in the range of -1000 to -10000 V. The duration of the high pulse
voltage asymmetrical AC waveforms can be in the range of 1 to 20
msec. The substrate temperature during the sputtering process can
be in the range of -100 C and +200 C. The hardness of the
diamond-like coating formed on the substrate can be in the range of
5 to 70 GPa. The concentration of sp3 bonds in the carbon film can
be in the range of 10-80%. In some embodiments, the concentration
of sp2 bonds in the carbon film can be in the range of 80 and 100%.
In some embodiments, the feed gas is a noble gas such as Ar, He,
Ne, and Kr. In some embodiments, the feed gas is a mixture of a
noble gas and hydrogen. In some embodiments, the feed gas is a
mixture of a noble gas and a gas that contains carbon atoms. In
some embodiments, the feed gas is a mixture of a noble gas and
oxygen in order to sputter oxygenated carbon films CO.sub.x for
non-volatile memory devices or any other devices. The oxygen gas
flow can be in the range of 1-10000 sccm. The discharge current
density during the sputtering process can be 0.2-20 A/cm.sup.2. In
some embodiments, the amorphous carbon films are sputtered for
non-volatile memory semiconductor-based devices, for any other
semiconductor-based devices, or for tribological applications to
reduce friction between two moving surfaces, such as on piston
rings for automotive applications, or medical implants, such as
hips, screws, and stents, or cutting objects, such as scalpels,
scissors, or hair removal blades.
[0169] In some embodiments, the HEDP source with an asymmetric AC
discharge can be used to deposit thin-film materials for the
manufacturing of phase-change random-access memory (PCRAM) and
resistive random-access memory (ReRAM) devices. PCRAM and ReRAM can
improve speed, power efficiency, and reliability of storage and
retrieval as software and data are retained even when power is
absent. In some embodiments, it can be used to form thin film gate
wires with extremely low switching losses in picojoules at higher
switching frequencies.
[0170] In some embodiments, the hollow cathode target material is
aluminum. The feed gas can also be a mixture of argon and oxygen,
or argon and nitrogen. The feed gases pass through a gas activation
source. In some embodiments, feed gasses pass directly to the
vacuum chamber. PFN or PCN 124 generates the asymmetrical high
voltage AC waveform to provide HEDP magnetron discharge to sputter
hard .alpha.-Al.sub.2O.sub.3 or .gamma.-Al.sub.2O.sub.3 coating on
the substrate. The substrate temperature during the sputtering
process is in the range of 350 to 800 C.
[0171] HEDP magnetron discharge can be used for sputter etching the
substrate with ions from sputtering target material atoms and gas
atoms. A method of sputter etch processing with argon ions and
sputtered target material ions uses high negative substrate bias
voltage in the range of -900 to -1200 V. The gas pressure can be in
the range of 1 to 50 mTorr. The pulse power supply generates a
train of negative unipolar voltage pulses with frequency and
amplitude that provide resonance mode in the second tunable PFN or
PCN 124. In this case, the PFN or PCN 124 generates the high
voltage asymmetrical AC voltage waveform that provides HEDP
discharge. For example, a sputter etch process can be used to
sharpen or form an edge on a substrate for cutting applications,
such as surgical tools, knives, inserts for cutting tools, or razor
blades for hair removal applications, or for cleaning a substrate
by removing impurities to enhance adhesion. HEDP magnetron
discharge also can be used for ion implantation of ions from
sputtered target material atoms into a substrate. For ion
implantation, the negative bias voltage on the substrate can be in
the range of -900-15000 V. An ion implantation example includes the
doping of a silicon-based device or ion implantation to enhance
thin film adhesion to the substrate where the layer is forming.
[0172] In some embodiments, the electrically enhanced HEDP
magnetron sputtering source can be used for chemically enhanced
I-PVD deposition (CE-IPVD) of metal containing or non-metal films.
For example, in order to sputter carbon films with different
concentrations of sp3 bonds in the film, the cathode target may be
made from carbon material. The feed gas can be a noble gas and
carbon atoms containing gas, such as C.sub.2H.sub.2, CH.sub.4, or
any other gases. The feed gas can also contain H.sub.2. Carbon
films on the substrate are formed by carbon atoms from the feed gas
and from carbon atoms from the cathode target. The carbon films on
the substrate are formed by carbon atoms from the feed gas.
[0173] The advanced thin films, such as but not limited to carbon
films, sputtered with the electrically enhanced HEDP magnetron
sputtering source with noble gas, such as Argon, Neon, Helium and
the like, or reactive gas, such as Hydrogen, Nitrogen, Oxygen, and
the like can be used for hard mask applications in etch processes,
such as 3D NAND; for protectively coating parts, such as bearings,
camshafts, gears, fuel injectors, cutting tools, inserts for
cutting tools, carbide inserts, drill bits, broaches, reamers,
razor blades for surgical applications and hair removal, hard
drives, solar panels, optical filters, flat panel displays, thin
film batteries, batteries for storage, hydrogen fuel cell,
cutleries, jewelry, wrist watch cases and parts, coating metal on
plastic parts such as lamps, air vents in cars, aerospace
applications, such as turbine blades and jet engine parts, jewelry,
plumbing parts, pipes, and tubes; medical implants, such as stents,
joints, cell phone, mobile phone, iPhone, iPod, touch screen, hand
held computing devices, application specific integration circuits
and the like.
[0174] The carbon films sputtered with the electrically enhanced
HEDP magnetron sputtering source can be used to sputter thin ta-C
and CO.sub.x films for carbon-based resistive memory devices or as
transistor gate wires.
[0175] In some embodiments, the HEDP magnetron discharge with a
carbon target is used to grow carbon nanotubes. In some
embodiments, these nanotubes are used to build memory devices,
cosmetics, transistors and switching device gate wires, and/or
power electronics.
[0176] During the HEDP sputtering process, when the high-power
pulse asymmetric AC voltage waveform is applied to the magnetically
enhanced sputtering source, a pulse bias voltage can be applied to
the substrate to control ion bombardment of the growing film. In
some embodiments, during the HEDP sputtering process, when the
high-power pulse asymmetric AC voltage waveform is applied to the
magnetically enhanced sputtering source, a pulse bias voltage can
be applied to the substrate to control ion bombardment of the
growing film. The amplitude of the negative voltage can be in the
range of -10 V and -200 V. Trains of asymmetrical AC voltage
waveforms 602 are shown in FIG. 6 (a). Trains of negative voltage
DC pulses 603 applied to the substrate are shown in FIG. 6 (b). In
order to control time t1 when bias voltage pulse is applied to the
substrate, the high-power pulse resonance AC power supply and bias
power supply are synchronized. In this case, the controller from
the high-power pulse resonance AC power supply sends
synchronization pulses that correspond to the trains of
asymmetrical AC voltage waveforms to the controller from the bias
power supply. The bias power supply controller can set time
.DELTA.t1 in the range of 0-1000 .mu.s.
[0177] In some embodiments, the bias power supply includes an RF
power supply. FIG. 6 (c) shows a train of RF pulses 604 generated
by the RF bias power supply.
[0178] The method of generating resonance AC voltage waveforms for
the magnetically enhanced sputtering source can also be used to
generate resonance AC waveforms for the cathodic arc evaporation
sources that have widespread applications in the coating industry.
Resonance AC voltage wave waveforms, when connected with a
magnetically enhanced sputtering source, generate volume discharge.
Resonance AC voltage waveforms, when connected with an arc
evaporation source, generate point arc discharge. DC power supplies
generate and sustain continuous arc discharge on an arc evaporation
source with a carbon target. The arc current can be in the range of
40-100 A. The arc discharge voltage can be in the range of 20-120
V. A regulated voltage with a variable power source feeds the
high-power pulse programmable power supply. Specifically, the
high-power pulse asymmetric AC voltage waveform is generated by
having the regulated voltage source with variable power feeding a
regulated voltage to the high-power pulse supply with programmable
pulse voltage duration and pulse voltage frequency producing at its
output a train of regulated amplitude unipolar negative voltage DC
pulses with programmed pulse frequency and duration, and supplying
these pulses to a second tunable pulse forming network (PFN) or
pulse converting network (PCN) including a plurality of specialized
inductors and capacitors designed for pulse applications connected
in a specific configuration coupled to an arc evaporation source.
The resonance occurs in the PFN or PCN and in the already existing
arc discharge generated by the DC power supply. By adjusting the
pulse voltage amplitude, duration, and frequency of the unipolar
negative voltage DC pulses and tuning the values of the inductors
and capacitors in the second PFN or PCN coupled to an arc
evaporation source, a resonance pulsed asymmetric AC arc discharge
can be achieved.
[0179] Another method of producing a resonance pulsed asymmetric AC
arc discharge is to have fixed unipolar pulse power supply
parameters (amplitude, frequency, and duration) feeding a pulse
forming network, in which the numerical values of the inductors and
capacitors, as well as their configurations, are tuned to achieve
the desired resonance values on the arc evaporation source to form
a layer on the substrate. The tuning of the second PFN or PCN can
be performed manually with test equipment, such as an oscilloscope,
voltmeter, and current meter or other analytical equipment; or
electronically with a built-in software algorithm, variable
inductors, variable capacitors, and data acquisition circuitry. The
negative voltage from the pulse asymmetric AC voltage waveform
generates high-density plasma from the evaporated target material
atoms between the cathode target and the anode of the arc
evaporation source. The positive voltage from the pulse
asymmetrical AC voltage waveform attracts plasma electrons to the
cathode area and generates positive plasma potential. The positive
plasma potential accelerates evaporated target material ions from
the cathode target area towards the substrate that improves
deposition rate and ion bombardment on the substrate. The reverse
electron current can be up to 50% from the discharge current during
the negative voltage. In some embodiments, the arc evaporation
source may have one of a rotatable magnetic field, movable magnetic
field, or stationary magnetic field. The second tunable PFN or PCN
includes a plurality of capacitors and inductors. The resonance
mode associated with the second tunable PFN or PCN is a function of
the input unipolar voltage pulse amplitude, duration, and frequency
generated by the high-power pulse power supply; inductance,
resistance, and capacitance of the arc evaporation source, or any
other magnetically enhanced arc evaporation source; the inductance,
capacitance, and resistance of the cables between the second
tunable PFN or PCN and arc evaporation source; and a plasma
impedance of the arc evaporation source itself as well as the
evaporated material. In the resonance mode, the output negative
voltage amplitude of the high-power pulse voltage mode asymmetrical
AC waveform on the arc evaporation source exceeds the negative
voltage amplitude of the input unipolar voltage pulses into the
second tunable PFN or PCN by 1.1-5 times. The unipolar negative
high-power voltage output can be in the range of 400V-5000V. In the
resonance mode, the absolute value of the negative voltage
amplitude of the asymmetrical AC waveform can be in the range of
750-5000 V. In the resonance mode, the output positive voltage
amplitude of the asymmetrical AC waveform can be in the range of
100-2500 V.
[0180] In the resonance mode, the negative voltage amplitude of the
output AC waveform can reach a maximum absolute value at which
point a further increase of the input voltage to the second tunable
PFN or PCN will not result in a voltage amplitude increase, but
rather an increase in the duration of the negative pulse in the
asymmetric AC waveform. In some embodiments, in the resonance mode,
the negative voltage amplitude of the output AC waveform can reach
a maximum absolute value, at which point a further increase of the
input voltage to the second tunable PFN or PCN will result in a
positive voltage amplitude increase. In some embodiments, the
frequency of the unipolar voltage pulses is in the range of 1 kHz
and 10 kHz. In some embodiments, the duration of the unipolar
voltage pulses is in the range of 3-20 .mu.s. In some embodiments,
the duration of the unipolar voltage pulses is in the range of
0.01-2.9 .mu.s. In some embodiments, the duration of the unipolar
voltage pulses is in the range of 20-2000 .mu.s. Asymmetrical AC
voltage waveforms significantly influence the size of the cathode
arc spot and velocity. In some embodiments, the generation of the
resonance AC voltage waveforms reduces the formation of
macro-particles from the evaporated cathode target material. The
arc discharge current during the negative portion of the AC voltage
can be in the range of 200-3000 A. The arc discharge current during
the positive portion of the AC voltage has a lower value and can be
in the range of 10-500 A. The arc AC discharge current and arc
discharge AC voltage waveforms are shown in FIG. 13.
[0181] In an embodiment, a high-power pulse resonance AC power
supply 700, as compared with the high-power pulse resonance AC
power supply 102 shown in FIG. 1(g), includes a high-frequency
high-power pulsed power supply 701 with a programmable voltage
pulse frequency and amplitude as shown in FIG. 8 (a). The high
frequency high-power pulsed power supply 701 generates pulse
negative, unipolar oscillatory voltage waveforms with a frequency
in the range of 100 KHz to 5 MHz and a duration t1 in a range of
0.05 .mu.s to 200 .mu.s. The absolute value of the voltage of these
waveforms is in a range of 500 V to 5000 V. The frequency of these
pulses with negative unipolar voltage waveforms is in a range of 5
Hz to 200 KHz.
[0182] Pulse negative unipolar oscillatory voltage waveforms 800
are shown in FIG. 8 (c). The second tunable PFN or PCN 124, which
is in resonance mode for these pulses, generates a high-power
resonance asymmetrical AC waveform. The resonance mode can be
achieved by adjusting the values of inductors L1, L2, L3, and L4,
and by adjusting the values of capacitors C1 and C2 for a
particular shape of the pulse negative unipolar oscillatory voltage
waveforms, their frequency, type of process gas, target material,
and magnetic field strength of the hollow cathode sputtering source
702. The resonance mode is defined as the prevailing conditions
when the adjustment of the frequency and amplitude of the plurality
of negative unipolar oscillatory voltage waveforms 800 generate the
plurality of asymmetrical AC voltage waveforms 801 with positive V+
and negative V- voltages shown in FIGS. 8 (c, d). Further increase
of the oscillatory voltage waveform amplitude causes an increase in
the value of the positive portion of the AC voltage waveform. By
adjusting time t1, r t2, or both t1 and t2, double negative peak
asymmetrical AC voltage waveforms 802 can be achieved as shown in
FIG. 8 (d). FIG. 8 (b) shows a partial modulated pulsed dc
non-resonance pulse discharge.
[0183] In an embodiment, a magnetically and electrically enhanced
HEDP sputtering source 100 shown in FIG. 1(g) has a hollow cathode
target 103 that includes two parts as shown in FIG. 9 (a) and FIG.
9 (b). FIG. 9 (a) shows the hollow cathode target 103 that includes
pieces 703 and 705. These two pieces are attached to a copper
backing plate by a clamp 704. FIG. 9 (b) shows the hollow cathode
target that includes pieces 707 and 708. These two pieces are
bonded to a copper backing plate 706. The magnetically and
electrically enhanced HEDP sputtering source can have a diameter in
the range of 1 cm to 100 cm. The peak power density can be in the
range of 100 W/cm.sup.2 to 20 kW/cm.sup.2. The average power
density can be in the range of 50 W/cm.sup.2 to 150 W/cm.sup.2.
[0184] In an embodiment, the hollow cathode target 103 includes two
pieces 710 and 709 as shown in FIG. 10 (a). The piece 709 has
magnetic field lines 715 and the piece 710 has magnetic field lines
714. Each of these pieces is connected to different high-power
pulse resonance AC power supplies 711 and 712. The block diagram of
these high-power pulse resonance AC power supplies is shown in FIG.
8 (a). The high-power pulse resonance AC power supplies 711 and 712
generate AC voltage waveforms 715 and 716 shown in FIGS. 10 (a) and
10 (b). A time shift between negative voltage peaks 717 and 718 is
controlled by controller 719. In an embodiment, the power supply
711 sends a synchro pulse to power supply 712 to initiate the start
of power supply 712. In an embodiment, the power supply 712 sends a
synchro pulse to power supply 711 to initiate the start of power
supply 711.
[0185] In an embodiment, a magnetically enhanced HEDP sputtering
source that is shown in FIG. 1 (g) includes an additional magnetic
assembly positioned adjacent to the side walls 104 as shown in FIG.
1 (h). The magnetic assembly may have permanent magnets,
electromagnets, or a combination of permanent magnets and
electromagnetics.
[0186] The method of generating resonance AC voltage waveforms for
the magnetically enhanced sputtering source and high-power pulse
resonance AC power supply 700 can also be used to generate
resonance AC waveforms for cathodic arc evaporation sources.
High-power pulse resonance AC power supply 700 can be used for all
applications in which the high-power pulse resonance AC power
supply 102 can be used.
[0187] In an embodiment, a high-power pulse resonance AC power
supply 810 includes an AC power supply 811 and PFN 812 as shown in
FIG. 11. High-power AC power supply 811 can generate different AC
voltage waveforms at the output as shown in FIGS. 12 (a, b, c, d,
e, f). The frequency of these voltage waveforms can be in the range
of 3 KHz to 100 KHz. The peak voltage amplitude can be in the range
of 100 V to 1000 V. The PFN includes a step-up transformer 813, a
diode bridge 814, a plurality of inductors 815, 816, 817, 818 and a
plurality of capacitors 819 and 820. This PFN converts AC voltage
waveforms to an asymmetrical complex AC voltage waveform during the
resonance mode as shown in FIG. 11. AC voltage waveforms and
frequencies that correspond to this particular AC voltage waveform
are associated with specific values of inductors (815, 816, 817 and
818) and capacitors (819, 820) in order to generate the resonance
mode and form, at the output, the asymmetrical AC voltage waveform.
In an embodiment, the PFN does not have a diode bridge.
[0188] In an embodiment, the high-power pulse resonance AC power
supply can be connected to the HEDP magnetron sputtering source and
RF power supply simultaneously. The frequency of the RF power
supply can be in the range of 500 kHz to 30 MHz. The RF power
supply can operate in continuous mode or pulsed mode. In an
embodiment, the RF power supply turns on before the high-power
pulse resonance AC power supply turns on in order to provide stable
plasma ignition for plasma that will be generated with the
high-power pulse resonance AC power supply. The RF power supply can
be turned off after the high-density plasma is generated. In an
embodiment, the RF power supply operates in continuous mode
together with the high-power pulse resonance AC power supply. This
operation reduces parasitic arcs during the reactive sputtering
process. This operation is beneficial for sputtering ceramic target
materials and target materials with low electrical conductivity,
such as those containing B, Si, and the like.
[0189] The output voltage waveforms from the high-power pulse
resonance AC power supply are shown in FIG. 14 (a, b). The second
negative peak 812 can be generated by controlling parameters of the
PFN, such as inductors, capacitors and the transformer (if
applicable) as shown in FIG. 14 (a). The peak 812 has a significant
influence on the probability of generating arcs during reactive
sputtering. The plasma that is generated during this peak helps to
ignite high-density plasma during the first negative peak 811. The
second peak 812 may be triangular, sinusoidal or rectangular in
shape. The rectangular shape of the second negative peak 814 is
shown in FIG. 14 (b). The value and duration of the peak 812 helps
to control the energy of ions coming to the substrate. The duration
t.sub.s can be in the range of 2 .mu.s to 50 .mu.s. The amplitude
V.sub.s can be in the range of 200 V to 1000 V. The greater the
amplitude and/or duration of the second peak is, the less the ion
energy will be. This arrangement is of particular importance for
sputtering ta-C films when high ion energy can affect the structure
of the growing film.
[0190] A high-power pulse resonance AC power source 500 is shown in
FIG. 15 (a), and includes a HIPMIS power supply 540, which includes
a regulated voltage source with variable power feeding 511, a
high-power pulsed power supply 512 with built-in PFN 502 and
programmable voltage pulse frequency and amplitude, and a second
tunable PFN or pulse converter network (PCN) 510. The high-power
pulsed power supply with programmable voltage pulse frequency and
amplitude 540 includes a computer 509 and controller 508. The
regulated voltage source with variable power feeding 511 supplies
voltage in the range of 400-5000 V to the high-power pulsed power
supply 512 with built-in PFN 502 with programmable voltage pulse
frequency and amplitude. The high-power pulsed power supply with
programmable voltage pulse frequency and amplitude 540 generates
and provides a train of unipolar negative voltage DC pulses to the
tunable PCN 510. The amplitude of the unipolar negative voltage DC
pulses is in the range of 400 to 5000 V, and the duration of each
of the voltage pulses is in the range of 1 to 100 .mu.s. The
distance between voltages pulses is in the range of 0.4 to 1000
.mu.s, thus controlling the frequency to be between 0.1 to 400 kHz.
In some embodiments, there is a step-up or a step-down transformer
(not shown) between the high-power pulsed power supply 512 with the
built in PFN 502 with programmable voltage pulse frequency and
amplitude and the tunable PCN 510 to achieve a desired pulsed
resonance AC asymmetric discharge on an HEDP source 100. The
tunable PCN 510 includes a plurality of specialized variable
inductors L1-Ln and a plurality of specialized variable capacitors
C1-Cn 503 for high-power pulse applications. The value of these
inductors and capacitors 503 can be controlled by a central
processing unit (CPU) 507. In some embodiments, at least one
inductor and/or at least one capacitor 503 is variable, and their
values are computer controlled. The values of inductors L1-Ln are
in the range of about 0 to 1000 .mu.H each. Capacitors C1-Cn have
values in the range of 0 to 1000 .mu.F each. The high-power pulse
programmable power supply 540 is connected to controller 508 and/or
computer 509. Controller 508 and/or computer 509 control output
values and timing of the power supply 540. The power supply 540 can
also operate as a standalone unit without connection to the
controller 508 and/or computer 509.
[0191] The high energy density plasma (HEDP) magnetically enhanced
sputtering source 100, which generates a pulse resonance asymmetric
AC plasma discharge 545, is also shown in FIG. 15 (a) and includes
output current and voltage monitors 542, 543, respectively. The
current and voltage monitors 542, 543 are connected to an arc
suppression circuit 127. If the current monitor 542 detects a high
current and the voltage monitor 543 detects a low voltage, the arc
suppression circuit 127 is activated. It is to be noted that the
voltage monitor 543 is connected to an output of the tunable PCN
510. The arc suppression circuit 127 provides a signal to stop
generating incoming voltage pulses from the power supply 540 to the
tunable PCN 510, and connects the output of the tunable PCN 510
through switch 131 to ground or to a positive electrical potential
generated by a power supply 130 to eliminate arcing as shown in
FIG. 15 (a). The hollow cathode is shown as a C-shaped structure
514 coupled to the output of the tunable PCN 510.
[0192] In FIGS. 15 (b),(c), the unipolar negative pulsed DC output
from power supply 540 is programmed to produce a plurality of
pulses with two different voltage levels V7, V8, and defined pulse
width and frequency in two defined timed pulse bursts B1, B2 that
are fed to the tunable PCN 510 causing a pulsed resonance AC
asymmetric discharge on the HEDP source 100. In resonance,
V7<V9, V8<V10, and the value of the resonance positive
voltage on the output of the tunable PCN 510 is directly correlated
to the pulsed resonance current during the negative cycle.
[0193] In FIGS. 15 (d),(e), the unipolar negative pulsed DC output
from power supply 540 is programmed to produce a plurality of
pulses with controlled voltage rise-time and fall-time with two
different voltage levels V7, V8 and defined pulse width and
frequency in two defined timed pulse bursts B3, B4 feeding the
tunable PCN 510 and causing a pulsed resonance AC asymmetric
discharge on the HEDP source 100. In resonance, V7<V9,
V8<V10, and the value of the resonance positive voltage on the
output of the tunable PCN 510 is directly correlated to the pulsed
resonance current during the negative cycle.
[0194] In FIG. 15 (f), the unipolar negative pulsed DC output from
power supply 540 is programmed to produce a plurality of pulses
with voltage level Vim and defined pulse width and frequency in
defined timed pulse bursts B5 feeding the tunable PCN 510, and
causing a non-resonance discharge on the HEDP source 100. In this
case, the voltage input to the tunable PFN 510 V1 is equal to
voltage output V1.sub.out.
[0195] In FIG. 15(g), the unipolar negative pulsed DC output from
power supply 540 is programmed to produce a plurality of pulses
with voltage level V2 and defined pulse width and frequency in
defined timed pulse bursts B6 feeding the second PFN or PCN 510,
and causing a non-resonance pulsed DC modulated discharge on the
HEDP source 100. In this case, the voltage input V2 to the tunable
PCN 510 is equal to voltage output V3.
[0196] In FIG. 15(h), the unipolar negative pulsed DC output from
power supply 540 is programmed to produce a plurality of pulses
with voltage level V4 and defined pulse width and frequency in
defined timed pulse bursts B7 feeding the tunable PCN 510, and
causing a resonance pulsed AC modulated discharge on the HEDP
source 100. In this case, the voltage input to the tunable PCN 510
is V4<V5 when in resonance mode. The value of voltage V6 is
directly correlated to the peak pulsed resonance current during the
negative cycle and the pulse switching frequency from power supply
540.
[0197] In FIG. 15(i), the unipolar negative pulsed DC output from
power supply 540 with defined pulse voltage rise-time and fall-time
is programmed to produce a plurality of pulses with voltage level
V1 and defined pulse width and frequency in defined timed pulse
bursts B8 feeding the tunable PCN 510, and causing a non-resonance
discharge on the HEDP source 100. In this case, the voltage input
to the tunable PCN 510 V1 is equal to voltage output V1 out.
[0198] In FIG. 15(j), the unipolar negative pulsed DC output from
power supply 540 with defined pulse voltage rise-time and fall-time
is programmed to produce a plurality of pulses with voltage level
V2 with defined pulse width and frequency in defined timed pulse
bursts B9 feeding the tunable PCN 510 causing a non-resonance
pulsed DC modulated discharge on the HEDP source 100. In this case,
the voltage input V2 to the tunable PCN 510 is equal to the voltage
output V3.
[0199] In FIG. 15(k), the unipolar negative pulsed DC output from
power supply 540 with defined pulse voltage rise-time and fall-time
is programmed to produce a plurality of pulses with voltage level
V4 and defined pulse width and frequency in defined timed pulse
bursts B10 feeding the tunable PCN 510 causing a resonance pulsed
AC modulated discharge on the HEDP source 100. In this case, the
voltage input to the tunable PCN 510 is V4<V5 when in resonance
mode. The value of voltage V6 is directly correlated to the peak
pulsed resonance current during the negative cycle and the pulse
switching frequency from power supply 540.
[0200] In FIGS. 15 (l),(m), the unipolar negative pulsed DC output
from power supply 540 is programmed to produce a plurality of
pulses with two different controlled voltage levels V7, V8 and
defined pulse width and frequency in two defined timed pulse bursts
B12, B13, in which B11 is the sum of B12 and B13, feeding the
tunable PCN 510, and causing a mixed discharge with pulsed
non-resonance and pulsed resonance AC asymmetric discharge on the
HEDP source 100. In resonance, V7=V9, V8<V10, and the value of
the resonance positive voltage on the output of the tunable PCN 510
is directly correlated to the peak pulsed resonance current during
the negative cycle and the pulse switching frequency from power
supply 540.
[0201] A magnetically and electrically enhanced HEDP sputtering
source 100 shown in FIG. 16 (a) includes a hollow cathode magnetron
101 and the high-power pulse power supply 540, which includes the
high-power AC/DC convertor and cap charger source 508, 509, the
high-power pulsed power supply with programmable voltage pulse
frequency and amplitude 512 with built-in PFN 502, and the tunable
PCN 503, which in resonance mode, generates a high-power resonance
asymmetrical AC waveform.
[0202] The hollow cathode magnetron 101 includes a hollow cathode
target 103. The hollow cathode target 103 has side walls 104 and a
bottom part 105 as shown in FIGS. 16 (a), (b). An anode 106 is
positioned around the side walls 104. Magnets 107, 108 and magnetic
pole piece 109 are positioned inside a water jacket 110. The water
jacket 110 is positioned inside a housing 111. The hollow cathode
target 103 is bonded to a copper backing plate 112. Magnets 107,
108 and magnetic pole piece 109 generate magnetic field lines 113,
114 that terminate on the bottom part 105 and form a magnetron
configuration and some of the magnetic field 113, 114 terminates on
the side wall. Magnetic pole piece 109 is positioned on a supporter
124. Magnetic field lines 115, 116 terminate on the side walls 104.
Water jacket 110 has a water inlet 117 and a water outlet 118. The
water inlet 117 and water outlet 118 are isolated from housing 111
by isolators 121. Water jacket 110 and, therefore, hollow cathode
target 101 are connected to the tunable PCN 510 and the PCN 510
generates the resonance asymmetric AC discharge on the hollow
cathode, which is connected to the high-power pulse power supply
540. The following chemical elements, or a combination of any two
or more of these elements, can be used as a cathode material: B, C,
Al, Si, P, S, Ga, Ge, As, Se, In, Sn, Sb, Te, I, Tl, Pb, Bi, Sc,
Ti, Cr, Mn, Fe, Co, Ni, Cu, Zn, Y, Zr, Nb, Mo, Tc, Ru, Rh, Pd, Ag,
Cd, Lu, Hf, Ta, W, Re, Os, Ir, Pt, Au, La, Ce, Pr, Nd, Pm, Sm, Eu,
Gd, Tb, Dy, Ho, Er, Tm, Yb, Be, Mg, Ca, Sr, and/or Ba. A
combination of these chemical elements with the gases O2, N2, F,
Cl, and/or H2 can also be used as the cathode material.
[0203] A magnetically and electrically enhanced HEDP sputtering
source 100 shown in FIG. 17 (a) includes a hollow cathode magnetron
101 and the high-power pulse power supply 540, which includes the
high-power AC/DC convertor and cap charger source 508,509, the
high-power pulsed power supply with programmable voltage pulse
frequency and amplitude 512, and built-in PFN 502, and the tunable
PCN 503, and voltage and current monitor 504, which in resonance
mode, generates a high-power resonance asymmetrical AC
waveform.
[0204] The hollow cathode magnetron 101 includes a hollow cathode
target 516. The hollow cathode target 516 has side walls 515
machined on an angle with a range of about 1-75 degrees, a bottom
part 514, and a center post 541 that can be shaped as a straight
cylinder, which is hollow or solid. The walls of the cylinder 541
can be machined on an angle with a range of about 1-75 degrees, as
shown in FIGS. 17 (a), (b). An anode 106 is positioned around the
side walls 515. Magnets 107, 108, and magnetic pole piece 109 are
positioned inside a water jacket 110. The water jacket 110 is
positioned inside a housing 111. The hollow cathode target 516 is
bonded to a copper backing plate 112. Magnets 107, 108 and magnetic
pole piece 109 generate magnetic field lines 113, 114 that
terminate on the bottom part 514 and form a magnetron
configuration. Some of the magnetic fields 113, 114 terminate on
the side wall 516 and center pole 541. Magnetic pole piece 109 is
positioned on a supporter 124. Magnetic field lines 115, 116
terminate on the side walls 515 and center pole 541. Water jacket
110 has a water inlet 117 and a water outlet 118. The water inlet
117 and water outlet 118 are isolated from housing 111 by isolators
121. Water jacket 110 and, therefore, hollow cathode target 101 are
connected to a PCN 503, and the PCN 503 produces the resonance
asymmetric AC discharge on the hollow cathode that is connected to
the high-power pulse power supply 540 producing unipolar negative
voltage pulses. The following chemical elements, or a combination
of any two or more of these elements, can be used as a cathode
material: B, C, Al, Si, P, S, Ga, Ge, As, Se, In, Sn, Sb, Te, I,
Tl, Pb, Bi, Sc, Ti, Cr, Mn, Fe, Co, Ni, Cu, Zn, Y, Zr, Nb, Mo, Tc,
Ru, Rh, Pd, Ag, Cd, Lu, Hf, Ta, W, Re, Os, Ir, Pt, Au, La, Ce, Pr,
Nd, Pm, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb, Be, Mg, Ca, Sr, and/or
Ba. A combination of these chemical elements with the gases O2, N2,
F, Cl, and/or H2 can also be used as the cathode material.
[0205] A magnetically and electrically enhanced HEDP sputtering
source 100 shown in FIG. 18 (a) includes the hollow cathode
magnetron 101 and the high-power pulse power supply 540, which
includes the high-power AC/DC convertor and cap charger source
508,509, the high-power pulsed power supply with programmable
voltage pulse frequency and amplitude 512 with built-in PFN 502,
tunable PFN or PCN 503, which in resonance mode, generates a
high-power resonance asymmetrical AC waveform, and a high frequency
generator 518 operating in continuous or pulsed mode at 100 kHz to
60 MHz with a matching network. The output frequency can be a mixed
frequency from high frequency generator 518. The high frequency
generator 518 output and the PCN 503 can be synchronized to be
pulsed in-phase or out-of-phase with the output of the PCN 503.
[0206] The hollow cathode magnetron 101 includes a hollow cathode
target 103. The hollow cathode target 103 has side walls 104 and a
bottom part 105 as shown in FIGS. 18 (a), (b). An anode 106 is
positioned around the side walls 104. Magnets 107, 108, and
magnetic pole piece 109 are positioned inside a water jacket 110.
The water jacket 110 is positioned inside a housing 111. The hollow
cathode target 103 is bonded to a copper backing plate 112. Magnets
107, 108 and magnetic pole piece 109 generate magnetic field lines
113, 114 that terminate on the bottom part 105 and form a magnetron
configuration and some of the magnetic field 113, 114 terminates on
the side wall. Magnetic pole piece 109 is positioned on a supporter
124. Magnetic field lines 115, 116 terminate on the side walls 104.
Water jacket 110 has a water inlet 117 and a water outlet 118. The
water inlet 117 and water outlet 118 are isolated from housing 111
by isolators 121. Water jacket 110 and, therefore, hollow cathode
target 101 are connected to a high frequency generator 518 and a
PFN or PCN 503, and the PFN or PCN 503 provides the resonance
asymmetric AC discharge on the hollow cathode connected to a
high-power pulse power supply 540 producing unipolar negative
voltage pulses. The following chemical elements, or a combination
of any two or more of these elements, can be used as a cathode
material: B, C, Al, Si, P, S, Ga, Ge, As, Se, In, Sn, Sb, Te, I,
Tl, Pb, Bi, Sc, Ti, Cr, Mn, Fe, Co, Ni, Cu, Zn, Y, Zr, Nb, Mo, Tc,
Ru, Rh, Pd, Ag, Cd, Lu, Hf, Ta, W, Re, Os, Ir, Pt, Au, La, Ce, Pr,
Nd, Pm, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb, Be, Mg, Ca, Sr, and/or
Ba. A combination of these chemical elements with the gases O2, N2,
F, Cl, and/or H2 can also be used as the cathode material.
[0207] The hollow cathode magnetron 101 from the magnetically and
electrically enhanced HEDP sputtering source 100 is mounted inside
a vacuum chamber 401 to construct the magnetically and electrically
enhanced HEDP sputtering apparatus 519 shown in FIG. 19 (a). The
vacuum chamber 401 contains feed gas and plasma, and is coupled to
ground. The vacuum chamber 401 is positioned in fluid communication
with a vacuum pump 402, which can evacuate the feed gas from the
vacuum chamber 401. Typical baseline pressure in the vacuum chamber
401 is in a range of 10-6 to 10-9 Torr. The vacuum chamber contains
a ring RF HDP gas source or magnetically enhanced chemical vapor
deposition (CVD) source 520 connected to an RF power supply 524 in
the range of about 1-60 Mhz, and typically 13.56 MHz, and a
matching network and an inductor grounding the cathode part of the
RF source or magnetically enhanced chemical vapor deposition (CVD)
source. In some embodiments, the gas source 520 can be magnetically
coupled to the hollow cathode magnetron 101 or the substrate
support 408 or both. The gas source 520 improves gas dissociation
and plasma ignition voltage on the hollow cathode 101. The gas
source 520 can be fed gas through a mass flow controller 404. The
gas flow is in a range of about 1 to 100000 SCCM depending on
plasma operating conditions, pumping speed of a vacuum pump 403,
process conditions, and the like. Typical gas pressure in the
vacuum chamber 401 during a sputtering process is in a range of
about 0.5 to 1000 mTorr. In some embodiments, a plurality of gas
inlets and a plurality of mass flow controllers sustain a desired
gas pressure during the sputtering process. The plurality of gas
inlets and plurality of mass flow controllers may be positioned in
the vacuum chamber 401 at different locations. The feed gas can be
a noble gas, such as Ar, Ne, Kr, Xe, a reactive gas, such as N2,
O2, or any other gas suitable for sputtering or reactive sputtering
processes. The feed gas can also be a mixture of noble and reactive
gases fed through the gas source 520 or fed directly into the
chamber.
[0208] The magnetically enhanced HEDP sputtering apparatus 400
includes a substrate support 408 that holds a substrate 407 or
other work piece for plasma processing. The substrate support 408
is electrically connected to a bias voltage power supply 409 or
multiple bias voltage power supply 409. The bias voltage power
supply 409 can include a radio frequency (RF) power supply,
alternating current (AC) power supply, very high frequency (VHF)
power supply, and/or direct current (DC) power supply. The bias
power supply 409 can operate in continuous mode or pulsed mode. The
bias power supply 409 can be a combination of two different RF
power supplies that can provide different frequencies. In some
embodiment, a common exciter (CEX) phase controller can be used to
eliminate unwanted beat frequencies if two RF generators are used
as a bias supply 409. In some embodiments, a common exciter (CEX)
phase controller can be used to eliminate unwanted beat frequencies
between the bias RF generator 409 and the RF power supply of the
gas ring source 520. In this way, two RF generators can be
phase-locked together so that the RF generators run at the same
frequency with a fixed phase relationship between their outputs,
thereby preventing unwanted beat frequencies. The negative bias
voltage on the substrate is in a range of about 0 to -2000 V. In
some embodiments, the bias power supply generates a pulse bias with
different voltage pulse frequency, amplitude, and shape as shown in
FIG. 19 (b). In some embodiments, the voltage is a pulse voltage.
The negative substrate bias voltage can attract positive ions to
the substrate. The substrate support 408 can include a heater 414
that is connected to a temperature controller 421. The temperature
controller 421 regulates the temperature of the substrate 407. In
an embodiment, the temperature controller 420 controls the
temperature of the substrate 407 to be in a range of about -100 C
to (+1000) C.
[0209] A multiple hollow cathode magnetron 101 from the
magnetically and electrically enhanced HEDP sputtering source 100
connected to a PCN 503 is mounted inside a vacuum chamber 401 to
construct the magnetically and electrically enhanced HEDP
sputtering apparatus 582 shown in FIG. 20 (a). The vacuum chamber
401 contains feed gas and plasma, and is coupled to ground. The
vacuum chamber 401 is positioned in fluid communication with a
vacuum pump 402, which can evacuate the feed gas from the vacuum
chamber 401. Typical baseline pressure in the vacuum chamber 401 is
in a range of about 10-6 to 10-9 Torr. The vacuum chamber contains
a remote or ring RF HDP gas source 571 connected to an RF power
supply 524 in the range of about 1-60 Mhz, and typically 13.56 MHz,
and a matching network 546 and an inductor grounding the cathode
part of the gas source 520. In some embodiments, the gas source can
be magnetically coupled to the hollow cathode magnetron 10, the
substrate support 408, or both. In this embodiment, the substrate
408 can be a single object, such as a metal block or multiple
components mounted on a substrate holder moving in rotary motion in
front of the HEDP sputtering source or sources 100. The gas source
520 improves gas dissociation and plasma ignition voltage on the
hollow cathode 101. The gas source 520 can be fed gas through a
mass flow controller 404. The gas flow is in a range of about 1 to
100000 SCCM depending on plasma operating conditions, pumping speed
of a vacuum pump 403, process conditions, and the like. Typical gas
pressure in the vacuum chamber 401 during a sputtering process is
in a range of about 0.5 to 50 mTorr. The feed gas can be a noble
gas, such as Ar, Ne, Kr, Xe, a reactive gas, such as N2, O2, or any
other gas suitable for sputtering or reactive sputtering processes.
The feed gas can also be a mixture of noble and reactive gases
through the gas source 520 or fed directly into the chamber.
[0210] The magnetically enhanced HEDP sputtering apparatus 582
includes a substrate support 408 that holds a substrate 407 or
other work piece for plasma processing. The substrate support 408
can be stationary or rotating at about 1-200 rpm. The substrate
support 408 is electrically connected to a bias voltage power
supply 409 or multiple bias voltage power supplies 409. The bias
voltage power supply 409 can include a radio frequency (RF) power
supply, alternating current (AC) power supply, very high frequency
(VHF) power supply, and/or direct current (DC) power supply. The
bias power supply 409 can operate in continuous mode or pulsed
mode. The bias power supply 409 can be a combination of two
different RF power supplies that can provide different frequencies.
The negative bias voltage on the substrate is in a range of about 0
to -2000 V. In some embodiments, the bias power supply generates a
pulse bias with different voltage pulse frequency, amplitude, and
shape as shown in FIG. 20 (b). In some embodiments, the bias power
supply generates an AC bias with different voltage pulse frequency,
amplitude, and shape as shown in FIG. 20 (C). In some embodiments,
the voltage is a pulse voltage. The negative substrate bias voltage
can attract positive ions to the substrate. The substrate support
408 can include a heater 414 that is connected to a temperature
controller 421. The temperature controller 421 regulates the
temperature of the substrate 407. In an embodiment, the temperature
controller 420 controls the temperature of the substrate 407 to be
in a range of about -100 C to (+1000) C.
[0211] The hollow cathode magnetron 101 from the magnetically and
electrically enhanced HEDP sputtering source 100 is mounted inside
a vacuum chamber 401 to construct the magnetically and electrically
enhanced HEDP sputtering apparatus 570 shown in FIG. 21 (a). The
vacuum chamber 401 contains feed gas and plasma, and is coupled to
ground. The vacuum chamber 401 is positioned in fluid communication
with a vacuum pump 402, which can evacuate the feed gas from the
vacuum chamber 401. Typical baseline pressure in the vacuum chamber
401 is in a range of 10-6 to 10-9 Torr. The vacuum chamber contains
a remote RF HDP gas source 571 connected to an RF power supply 524
in the range of about 1-60 Mhz, and typically 13.56 MHz, a matching
network 546, and an inductor grounding the cathode part of the RF
source. In some embodiments, the gas RF source can be magnetically
coupled to the hollow cathode magnetron 101, or the substrate
support 408, or both. The gas source 571 improves gas dissociation
and plasma ignition voltage on the hollow cathode 101. The gas
source 571 can be fed gas through a mass flow controller 404. The
gas flow is in a range of about 1 to 100000 SCCM depending on
plasma operating conditions, pumping speed of a vacuum pump 403,
process conditions, and the like. Typical gas pressure in the
vacuum chamber 401 during a sputtering process is in a range of
about 0.5 to 50 mTorr. The feed gas can be a noble gas, such as Ar,
Ne, Kr, Xe, a reactive gas, such as N2, O2, or any other gas
suitable for sputtering or reactive sputtering processes. The feed
gas can also be a mixture of noble and reactive gases through the
RF source 571 or fed directly into the chamber.
[0212] The magnetically enhanced HEDP sputtering apparatus 570
shown in FIG. 21 (a) includes a substrate support 408 that holds a
substrate 407 or other work piece for plasma processing. The
substrate support 408 is electrically connected to a bias voltage
power supply 409 or multiple bias voltage power supply 409. The
bias voltage power supply 409 can include a radio frequency (RF)
power supply, alternating current (AC) power supply, very high
frequency (VHF) power supply, and/or direct current (DC) power
supply. The bias power supply 409 can operate in continuous mode or
pulsed mode. The bias power supply 409 can be a combination of two
different RF power supplies that can provide different frequencies.
The negative bias voltage on the substrate is in a range of about 0
to -2000 V. In some embodiments, the bias power supply generates a
pulse bias with different voltage pulse frequency, amplitude, and
shape as shown in FIG. 21 (b). In some embodiments, the voltage is
a pulse voltage. The negative substrate bias voltage can attract
positive ions to the substrate. The substrate support 408 can
include a heater 414 that is connected to a temperature controller
421. The temperature controller 421 regulates the temperature of
the substrate 407. In an embodiment, the temperature controller 420
controls the temperature of the substrate 407 to be in a range of
about -100 C to (+1000) C.
[0213] An embodiment of a magnetically enhanced CVD deposition
source magnetic field geometry is shown in FIG. 22 (a). This
geometry, on one side, forms a cusp magnetic field in a gap between
an anode and a hollow cathode target and, on another side, forms
magnetic field lines that cross a surface of the cathode
substantially perpendicular to the cathode surface. Therefore,
magnetic field lines from one side terminate on the cathode target
surface, and from another side the magnetic field lines terminate
in the gap on the pole piece that does not has the same potential
as a cathode target, and the pole piece is not a cathode target.
This magnetic field geometry does not confine secondary electrons
near the cathode target surface, as in conventional magnetron
sputtering sources. Instead, this magnetic field geometry allows
secondary electrons to move from the target surface toward the gap
between the cathode and the anode.
[0214] In the case of chemically enhanced ionized physical vapor
deposition (CE-IPVD) when negative voltage pulses are applied to
the cathode target, plasma is ignited and sustained in a reactive
gas atmosphere during the voltage pulse, the magnetic field lines
guide secondary electrons emitted by the cathode target surface
away from the cathode surface towards the gap between the hollow
cathode and anode. During this movement, the electrons dissociate
the feed gas molecules and ionize atoms. By the time these
electrons come in contact with the pole piece in the gap that
concentrates the cusp magnetic field in the gap, the electrons have
lost a portion of their initial energy. A portion of the secondary
electrons will drift back to the hollow cathode target surface due
to magnetic mirror effect or the presence of negative potential on
the pole piece. If these electrons reach the hollow cathode surface
during the time between voltage pulses, when the hollow cathode
target voltage is equal to zero, these electrons discharge a
positive charge on top of the cathode surface and significantly
reduce or eliminate the probability of arcing on the cathode target
surface during the CE-IPVD. The amount of electrons returning to
the hollow cathode surface can be controlled by selecting the
magnetic field geometry, gas pressure, amplitude, duration, the
distance between applied voltage pulses, and duration and value of
negative potential on the pole piece. The positive charge on the
hollow cathode target surface can be formed due to the generation
of low electrical conductivity films during the CVD process.
[0215] A magnetically enhanced CVD source has a hollow cathode
target and at least two rows of magnets 1101 and 1102 as shown in
FIG. 22 (a). The two rows of magnets face each other and provide a
magnetic field in the same direction (south-south or north-north)
and, therefore, generate cusp magnetic field geometry 1103 in the
gap 1113 between the hollow cathode target 1104 and the anode 105
where the anode is positioned on top of the hollow cathode target
1104. A pole piece 1106 is disposed between two rows of the magnets
1101, 1102. This pole piece 1106 can be made from a magnetic or
nonmagnetic material. If the pole piece 1106 is made from magnetic
material, the pole piece 1106 concentrates the cusp magnetic field
which can increase a magnetic mirror effect for the electrons
drifting from the cathode target surface towards the gap. There is
another pole piece 1109 positioned on top of the top row of magnets
1101. This pole piece 1109 is made from a magnetic material. The
pole piece 1109 is exposed to plasma through the gap 1110
positioned in the anode 1105. The pole pieces 1109 and 1106 can be
connected to power supply 1107 or can be grounded or isolated from
the ground.
[0216] In some embodiments, power supply 1107 is an RF power
supply. In some embodiments, pole piece 1106 is grounded through
inductor 1127 to eliminate the DC bias. Pole piece 1109 can be
connected to a different power supply and can have a different
potential than pole piece 1106. Pole pieces are isolated from the
anode 1106 and magnets 1101 and 1102 by isolators 1108. Magnetic
field lines from the bottom row of the magnets 1102 penetrate the
top surface of the hollow cathode target 1104 at a substantially 90
degree angle. Magnetic field lines 1112 from the top row of the
magnets terminate on the magnetic pole piece 1106 and 1109.
Magnetic field lines 1111 from the bottom row of magnet 102 crosses
over the magnetic pole pieces 1114, 115, magnet 1116, and cathode
target 104. Pole pieces 1114, 1115 are made from magnetic material.
Magnet 1116 enhances the magnetic field near the cathode target
surface. The cathode target 1104 is connected to power supply 1117.
The cathode target 1104 can be also connected to power supply 1118
through switch 1119. In some embodiments, power supply 1118 is an
RF power supply and power supply 1117 is a DC power supply. These
two power supplies 1117, 1118 generate an RF DC superimposed
discharge. In some embodiments only RF power supply 1118 is
connected to the cathode target 1104. In this case, a ground 1125
can be connected to the cathode target 1104 through inductor 1124
and switch 1126 to eliminate the DC bias. If the cathode target
1104 is inductively grounded, the RF discharge cannot generate a
constant negative DC voltage bias. In this case, there is no
sputtering from the cathode target 1104. In some embodiments, only
one power supply 1117 is connected to the cathode target 1104 and
generates negative voltage pulses.
[0217] Magnetic field 1111 lines that penetrate the hollow cathode
surface guide the emitted electrons from the hollow cathode target
surface 1104 to the gap between the anode and the hollow cathode
1104 as shown in FIG. 22 (b) by arrow 1120. By the time the emitted
electrons arrive at the gap, a portion of their initial energy has
been lost due to dissociation, ionization, and/or elastic and/or
non-elastic collisions with neutral atoms, ions, and/or other
electrons. One portion of the electrons reflect from point "A" due
to a magnetic mirror effect and another portion of the electrons
reflect from point "B" due to the presence of a negative potential
on pole piece 1106. The electrons drift back from the gap towards
the hollow cathode surface as shown by arrow 1121. Another portion
of the electrons drift towards the anode gap as shown by arrow
1122. These electrons reflect back from point "C" due to the
magnetic mirror effect, and from point "D" due to a negative
electric potential on the pole piece as shown by arrow 1123. If
pole piece 1109 is hidden under grounded anode 1105, the portion of
the electrons that were not reflected by the magnetic mirror effect
are absorbed by grounded anode 1110. Preferably, a negative voltage
on the pole pieces 106 is less than -50 V in order to prevent
possible sputtering from the pole piece. In some embodiments, short
negative voltage pulses with durations in the range of 5-100 .mu.s
and amplitudes in the range of 100-2000 V with a frequency of up to
about 100 kHz are applied to the pole piece 1106. Voltage pulse can
be triangle, rectangular, trapezoidal or have any shape. Voltage
pulse can be negative, bipolar, or positive. Application of the
negative high voltage pulses increase the energy of the electrons
reflected from the gap 1113 and, therefore, the plasma density.
[0218] FIG. 22 (c) shows negative voltage pulses generated by power
supply 1107 when the cathode target 1104 from the CVD source is
connected to the RF power supply. Pulsed negative voltage increases
electron energy in RF discharge and, therefore, increases plasma
density. As a result, in some embodiments, the negative voltage
bias generated by RF power supply 1117 is reduced during the pulse
from UD2 to UD1 as shown in FIG. 22 (d). FIG. 22 (e) shows negative
voltage pulses with different amplitude U1-U3 generated by power
supply 1107. Pulse voltage increases the amount of electrons and,
therefore, increases the plasma density. A greater negative pulse
voltage amplitude U3 generates greater plasma density and,
therefore, there is a less negative voltage bias UD1 generated by
the RF power supply. As a result, in some embodiments, the
discharge voltage generated by RF power supply 1117 is reduced
during the pulse as shown in FIG. 22 (f). The influences of the
frequency of the negative voltage pulses generated by power supply
1107 on discharge voltage generated by power supply 1117 or 1118
are shown in FIG. 221 (g, h). FIG. 22 (i) shows negative voltage
pulses generated by power supply 1107. As a result, in some
embodiments, the peak-to-peak voltage Upp1 generated by RF power
supply 117 connected to the inductively grounded cathode target
1104 is reduced during the pulse Upp2 as shown in FIG. 22 (j).
Depending on the voltage amplitude, duration, and shape of the
voltage pulses applied to the cathode, the voltage applied to the
pole piece 1106, 1109, and gas pressure, the electrons will move
back and forth between the cathode target and the gaps.
[0219] FIG. 23 (a) shows a cross-sectional view of an embodiment of
the magnetically enhanced CVD deposition source 1200. The
magnetically enhanced CVD deposition source 1200 includes a base
plate 1201. The base plate has an electrical ground potential. The
cathode assembly includes a water jacket 1202 and a hollow cathode
target 1207. The water jacket 1202 is electrically isolated from
the base plate 1201 with isolators 1205 and 1206. Water or another
fluid for cooling can move inside the water jacket 1202 through
inlet 1203 and can move outside the water jacket 1202 through
outlet 1204. The hollow cathode target 1207 is positioned on top of
water jacket 1202. The hollow cathode target 1207 is electrically
connected to a negative terminal of a power supply 1227 through a
water inlet 1203, transmission line 1230, and switch 1243. The
power supply 1227 can include a direct current (DC) power supply, a
pulsed DC power supply that generates unipolar negative voltage
pulses, a pulsed DC power supply that generates an asymmetrical
bipolar voltage pulses, a pulsed DC power supply that generates
symmetrical bipolar voltage pulses, an RF power supply, and/or a
high power pulsed power supply. Any of these pulsed power supplies
can generate different shapes, frequencies, and amplitudes of the
voltage pulses. These power supplies can work in power control
mode, voltage control mode, or in current control mode. The water
inlet 1204 is electrically connected to a negative terminal of a
power supply 1229 through a transmission line 1230, matching
network 1228, and switch 1242. A power supply 1229 can include a
radio frequency (RF) power supply, pulsed RF power supply, high
frequency (HF) power supply, pulsed HF power supply, or any
combination of these power supplies. The frequency of the applied
power can be in the range of 100 kHz-100 MHz. Power supply 1227 can
operate together with power supply 1229 or can operate alone
without connecting power supply 1229 to the cathode assembly. Power
supply 1229 can operate together with power supply 1227 or can
operate alone without connecting power supply 1227 to the cathode
assembly. The cathode 1207 can be powered with any combination of
the power supplies mentioned above. All of the above-mentioned
power supplies can operate in current control mode, voltage control
mode, and/or power control mode. Power supply 1227 and power supply
1229 can be connected to the same water inlet 1203. The cathode
target 1207 is formed in the shape of a round hollow shape, but can
be formed in other shapes, such as a rectangular hollow shape,
disc, and the like. The cathode target 1207 material can be
conductive, semi-conductive, and/or non-conductive. The following
chemical elements, can be used as a cathode material: B, C, Al, Si,
P, S, Ga, Ge, As, Se, In, Sn, Sb, Te, I, Tl, Pb, Bi, Sc, Ti, Cr,
Mn, Fe, Co, Ni, Cu, Zn, Y, Zr, Nb, Mo, Tc, Ru, Rh, Pd, Ag, Cd, Lu,
Hf, Ta, W, Re, Os, Ir, Pt, Au, La, Ce, Pr, Nd, Pm, Sm, Eu, Gd, Tb,
Dy, Ho, Er, Tm, Yb, Be, Mg, Ca, Sr, and/or Ba. A combination of
these chemical elements or their combination with the gases O2, N2,
F, Cl, and/or H2 can also be used as a cathode material. Power
supplies 1227, 1228, and switches 1243, 1242 are connected to the
controller 1280 and computer 1281. Controller 1280 and/or computer
1281 control the output voltage values and timing of the power
supplies 1227 and 1229. The power supplies 1227 and 1229 can be
synchronized.
[0220] The cathode assembly includes a stationary cathode magnetic
assembly 1222 positioned inside the water jacket 1202. The cathode
magnetic assembly 1222 in an embodiment includes a disc-shaped
magnetic pole piece made from magnetic material, such as iron. The
magnetic assembly 1222 is mounted on the plate 1223 that is made
from non-magnetic material. The presence of the magnetic pole piece
1222 provides for a perpendicular direction of the magnetic field
lines to the surface of the cathode. In an embodiment, the cathode
magnetic assembly (stationary or rotatable) includes a plurality of
permanent magnets and magnetic pole pieces. The shape of the
magnetic assembly 1222 determines the angle between the magnetic
field lines and a surface of the cathode. In an embodiment, the
magnetic assembly 1222 is rotatable. In an embodiment, the magnetic
assembly 1105 is kidney-shaped. The magnetic assembly 1222 can
rotate with a speed in the range of 1-500 revolutions per
minute.
[0221] A ring-shaped anode 1208 is positioned proximate to the
cathode target 1207. The anode 1208 and a hollow cathode target
1207 form a circular gap 1226. The electric field lines are
perpendicular to the magnetic field lines in the gap. Magnetic
field lines 1270 are substantially perpendicular to the cathode
target surface. In some embodiments, a top part of the anode 208
has a feed gas chamber and a gas outlet. In some embodiments, a
feed gas is fed through the gas pipe to the chamber and is
uniformly applied through the holes in the feed gas chamber. In
some embodiments, a feed gas is fed through the gap between the
hollow cathode target and the anode.
[0222] A magnet assembly that generates a cusp magnetic field 1225
has a round shape and is positioned behind the ring-shaped anode
1208 and hollow cathode target 1207. The magnetic assembly includes
magnetic ring-shaped pole pieces 1216, 1214, 1215 and a plurality
of permanents magnets 1213, 1212. The magnets 1213, 1212 are
positioned inside the magnet housing (not shown in FIG. 23 (a)).
The magnets 1212, 1213 face each other in the same direction in
order to generate a cusp magnetic field 1225 in the gap 1226. The
value of the magnetic field caused by the permanent magnets 1212,
1213 is in a range of 100-10000 G. Magnetic pole pieces 1216, 1214,
1215, and 1222 with magnets 1213, 1212 generate cusp magnetic field
1225. The pole piece 1216 is mounted on top of the support
1217.
[0223] Power supplies 1227, 1229 are connected to the controller
1280. Controller 1280 can be connected to a computer 1281.
Controller 1280, 1281 control the output voltage signals from the
power supplies 1227, 1229.
[0224] The pole piece 1214 is electrically isolated from the magnet
1212 by isolator 1218. The pole piece 1214 is electrically isolated
from the magnet 1213 by isolator 1219. The pole piece 1215 is
electrically isolated from the magnet 1213 by isolator 1220. The
pole piece 1215 is electrically isolated from the anode 1208 by
isolator 1221.
[0225] The magnetic fields 1225 are shaped to provide electron
movement between the cathode target 1207 and pole pieces 1214,
1215. During this movement, electrons ionize feed gas molecules
and/or atoms and sputtered target material atoms. Electrons that
are generated through ionization of the feed gas are trapped in the
magnetic fields 1225.
[0226] The pole pieces 1215, 1214 may have a different design. The
portion of the pole piece that is exposed to the gap 1226 has a cut
1233 in the middle as shown in FIG. 23 (b). The pole piece 1232 is
made from non-magnetic material. The shape and material of the pole
piece has an effect on point of reflections "B" and "A" as shown in
FIG. 22 (b).
[0227] Pole piece 1214 is connected to voltage control mode power
supply 1210 through electrode 1211. Electrode 1211 is isolated from
the base plate 1201 with isolator 1209. In some embodiments, power
supply 1210 is an RF power supply. In some embodiments, pole piece
1219 is grounded through an inductor.
[0228] In an embodiment, the magnets 1213, 1212 are electromagnets
as shown in FIG. 23 (c). Rather than using permanent magnets 213,
212 to generate magnetic field 1225, 1270, coils 1151, 1152 can be
used to generate cusp magnetic field 1225 and magnetic field 1270.
Electric current in the coils 1151, 1152 has a different direction
in order to form a cusp magnetic field. The value of the magnetic
field 1225 will depend on the electrical current value from the
power supplies 1155, 1156 and the quantity of wire turns 1153, 1154
in the coils. The power supplies 1155, 1156 can release pulsed
electrical current or continuous electrical current. Pulsed
electrical currents generate a pulsed magnetic field 1225, and a
continuous electrical current generates a continuous magnetic field
1225. The magnetic field value 1225 can be in the range of
500-10000 G. Power supplies 1156, 1155 can be connected to
controller 1280 and computer 1281.
[0229] FIG. 24 shows voltage pulse shapes that can be generated by
power supply 1210. The amplitude of negative voltage pulses can be
in the range of 100 and 2500 V. The pulse duration can be in the
range of 1-50 .mu.s.
[0230] FIGS. 25 (a, b, c, d) show different voltage pulse shapes,
amplitudes, and frequencies that power supply 1227 can provide.
Typically, in order to generate and sustain volume discharge, the
power supply 1227 operates in power control mode or in voltage
control mode. FIG. 25 (a) shows a continuous train of triangular
negative voltage pulses. The amplitude can be in the range of
100-3000 V. FIG. 25 (b) shows a train of negative voltage pulses
that has different voltage amplitudes. The voltage pulses with
amplitude V1 can be optimized to increase the dissociation rate of
feed gas molecules, and voltage pulses with amplitude V2 can be
optimized to increase the ionization rate of the target material
atoms and particular carbon atoms. The pulse voltage provides
energy to the electrons in the plasma discharge. For example,
voltage V1 is optimized to increase a dissociation rate of gas
molecules containing carbon atoms such as C2H2, CH4, CO, CO2, C3H8,
CH3OH, C2H5OH, CH3Cl, and the like. Also, it is important to
increase the dissociation rate of H2
(H2+e.fwdarw.H2*+e.fwdarw.H+H+e). The high-voltage pulse amplitude
V2 provides more energy to the electrons. Electrons collide with
gas molecules, gas atoms, and target material atoms. Typically, gas
atoms need more energy in order to be ionized and molecules need
less energy to dissociate. That is, if the voltage amplitude is
high then the probability of ionization of atoms will be high. The
pulse duration can be in the range of 1 microsecond-1 millisecond.
FIG. 25 (c) shows a pulse train of triangular negative voltage
pulses. The duration of the train of negative voltage pulses can be
in the range of 100 microseconds-10 milliseconds. The frequency of
the train of negative voltage pulses can be in the range of 100 Hz
and 20 KHz. FIG. 25 (d) shows a continuous voltage that can be in
the range of -100 and -2000 V.
[0231] FIG. 26 (a) and FIG. 26 (b) show continuous and pulsed RF
voltages, respectively, that can be provided by power supply 1228.
The RF power can be in the range of 100 W-10 kW. The RF frequency
can be in the range of 100 kHz-100 MHz. The frequency of RF pulses
can be in the range of 100 Hz-100 kHz. FIG. 26 (c) shows voltage on
the cathode when power supply 1227 provides a continuous train of
triangle voltage pulses and power supply 1228 simultaneously
provides continuous RF voltage. FIG. 26(d) shows voltage on the
cathode when power supply 1227 provides a pulse train of triangular
voltage pulses and power supply 1228 simultaneously provides pulse
RF voltage. Power supply 1227 can generate a continuous train of
rectangular negative voltage pulses as shown in FIG. 27 (a). Power
supply 1227 can generate a pulse train of rectangular negative
voltage pulses as shown in FIG. 27 (b). FIG. 27 (c) shows different
voltage pulse shapes in one pulse train. FIG. 27 (d) shows a train
of asymmetric bi-polar voltage pulses when the negative pulse
voltage has triangular shape. FIG. 27 (e) shows continuous and
pulsed RF voltages that can be provided by power supply 1228 or
1227 to the inductively grounded cathode target 1207.
[0232] The magnetically enhanced CVD deposition source 1200 can be
mounted inside the vacuum chamber 1270 in order to construct the
magnetically enhanced HDP-PVD deposition apparatus 1291 as shown in
FIG. 28. The vacuum chamber 1270 contains feed gas and plasma. The
vacuum chamber 1270 is coupled to ground 1288. The vacuum chamber
1270 is positioned in fluid communication with a vacuum pump 1287,
which can evacuate the feed gas from the vacuum chamber 1270.
Typical baseline pressure in the vacuum chamber 1270 is in a range
of 10.sup.-5-10.sup.-9 Torr.
[0233] A feed gas is introduced into the vacuum chamber 1270
through a gas inlet 1289 from feed gas sources. A mass flow
controller 1280 controls gas flow to the vacuum chamber 1270. In an
embodiment, vacuum chamber 1270 has many gas inlets and mass flow
controllers. The gas flow can be in a range of 1-100000 SCCM
depending on plasma operating conditions, pumping speed of the
vacuum pump 1287, process conditions, and the like. In some
embodiments, the feed gas is introduced through the gap 1226 from
the magnetically enhanced CVD source. Typical gas pressure in the
vacuum chamber 1201 during a CVD process is in a range of 0.1
mTorr-50 Torr. In an embodiment, a plurality of gas inlets and a
plurality of mass flow controllers sustain a desired gas pressure
during the CVD process. The plurality of gas inlets and plurality
of mass flow controllers may be positioned in the vacuum chamber
1270 at different locations. The feed gas can be a noble gas, such
as Ar, Ne, Kr, Xe; a reactive gas, such as N2, O2; any other gas
that is suitable for CVD processes. For depositing DLC or diamond
films, the feed gas contains atoms of carbon. For example, the
cathode target material is carbon. The feed gas can be C2H2, or CH4
or any other gases/vapors contains carbon atoms, such as CO, CO2,
C3H8, CH3OH, C2H5OH, and/or CH3Cl. Feed gas can also be a mixture
of different of gases. In some embodiments, the cathode target
material is not a carbon. The CVD source is connected to power
supply 2127 through water inlet 1203, and power supply 1229 is
connected to water outlet 1204. In some embodiments, only power
supply 1227 is connected to the CVD source. In some embodiments,
only power supply 1228 is connected to the CVD source.
[0234] The magnetically enhanced CVD apparatus 1291 includes a
substrate holder 1292 that holds a substrate 1283 or other work
piece for plasma processing. The substrate support 1284 is
electrically connected to bias voltage power supply 1290 through
the connector 1285. The bias voltage power supply 1290 can include
a radio frequency (RF) power supply, alternating current (AC) power
supply, very high frequency (VHF) power supply, and/or direct
current (DC) power supply. The bias power supply 1290 can operate
in continuous mode or in pulse mode. Pulse substrate bias voltage
can be synchronized with pulse voltage applied to the cathode
target. The bias power supply 1290 can be a combination of
different power supplies that can provide different frequencies.
The negative bias voltage on the substrate can be in a range of -1
and -2000 V. The negative substrate bias voltage can attract
positive ions to the substrate. In some embodiments, substrate
holder 1285 is inductively grounded to eliminate the DC bias and
connected to RF power supply. During the operation, there is no
negative constant bias. There are only RF voltage oscillations on
the surface of the substrate that promote dissociation of the
carbon containing gas. The substrate support 1284 can include a
heater 1284 connected to a temperature controller 1286 (exact
connection is not shown). The temperature controller 1284 regulates
the temperature of the substrate 1283. In an embodiment, the
temperature controller 1286 controls the temperature of the
substrate 1283 to be in a range of -20 C to +1500 C.
[0235] An additional magnet assembly between the CVD source and
substrate 1283 can be positioned inside the vacuum chamber 1270 or
outside the vacuum chamber 1270 in order to increase plasma density
near the substrate and, therefore, increase the dissociation rate
of the gas molecules and improve film uniformity on the
substrate.
[0236] The magnetically enhanced CVD source can be positioned in
the vacuum chamber 301 as shown in FIG. 29. Two rectangular
magnetically enhanced CVD sources 1304, 1305 are positioned inside
the vacuum chamber 1301. Vacuum pump 1302 can provide base pressure
up to 10-8 Torr. Two heaters 1308, 1309 control temperature of the
sample 1307. Two rectangular magnetically enhanced CVD sources
1304, 1305 are connected to the power supply 1312, 1315. The
magnetically enhanced CVD source 1305 is connected to RF power
supply 1318 through the switch 1319 and is connected to ground
through inductor 321 and switch 1320. The pole piece 1214 from the
magnetically enhanced CVD source 3105 is connected to power supply
324 through switch 1325. The pole piece 1214 from the CVD source
1304 is connected to power supply 1323 through switch 1322.
Substrate holder 1306 is connected to bias power supply 1313. Bias
power supply 1313, power supplies 1312, 1315, and switches 1316,
1310, 1318 are connected with controller 1314. Power supplies 1316,
1312 can provide any voltage pulses in any order as shown in FIGS.
25 (a, b, c, d), FIGS. 26 (a, b, c, d), and FIGS. 27 (a, b, c, d,
e). Bias power supply 1313 can be RF power supply with frequency is
in the range of 500 kHz and 30 MHz. Bias power supply 1313 can be
DC power supply or pulse DC power supply.
[0237] The substrate support1 1306 can provide for rotation of the
substrate 1307. The substrate support 1306 can have different parts
that rotate at different speeds. The substrate support 1306 can
hold one or more substrates 1130 or work pieces.
[0238] In an embodiment, the substrate 1307 is a part of automobile
engine and the coating is a hydrogenated diamond-like coating
(DLC). The DLC coating reduces the coefficient of friction of
moving parts in the automobile engine. The thickness of the DLC
coating is in a range of 0.1-50 microns depending on the particular
engine part. The parts that can be coated include the turbocharger,
valve, piston, piston ring, piston pin, heat exchanger, connecting
rod, crank end bearing, bearing, ball from any bearing, after
cooler, intercooler, rocker arm, injector, valve guide, push rod,
camshaft, fuel injection pump, oil pump, or any other part
associated with the automobile engine.
[0239] The method of CVD depositing a film on the substrate
includes the following steps. A first step is cleaning the surface
of the substrate by a sputter etch process with a noble gas. In
this step, the feed gas will be a noble gas, such as Ar. The gas
pressure can be in the range of 1-20 mTorr. The substrate bias can
be between -300 V and -1000 V. Magnetically enhanced CVD source
1305 operates in sputter etch mode. In this mode, only RF power
supply 1318 is connected to the cathode target from magnetically
enhanced CVD source 1305. The cathode target of the CVD source 1305
is inductively grounded in order to prevent sputtering from the
cathode target. Power supply 1324 generates voltage pulses with
amplitude, duration, and frequency to provide optimum energy in the
range of 150 eV to the electrons to generate Ar ions. In an
embodiment, power supply 1313 is RF power supply. In an embodiment,
power supply 1324 is not connected with pole piece 1214. In this
case, the RF power supply 1315 generates enough power to generate
significant amount of Ar ions. In some embodiments, power supply
1324 is an RF power supply. In some embodiments, pole piece 1214 is
grounded through an inductor.
[0240] A second step is RIE (reactive ion etch cleaning) cleaning
the surface of the substrate by a reactive gas, such as O2, H2. In
some embodiments, the cleaning is made using H2. In this step, the
feed gas is a reactive gas. The gas pressure can be in the range of
1 mTorr-100 mTorr. The substrate bias can be between -100 V and
-1000 V. Magnetically enhanced CVD sources 1305 operate in RIE
mode. In this mode, only RF power supply1 1318 is connected to CVD
source 1305. The cathode target from the magnetically enhanced CVD
source 1305 is inductively grounded. Power supply 1312 generates RF
discharge. Power supply 1324 generates voltage pulses with
amplitude, duration, and frequency to provide optimum energy in the
range of 150 eV to the electrons to generate reactive gas ions. In
an embodiment, the bias power supply 1313 is an RF power supply.
The voltage oscillation duration can be in the range of 3-50 .mu.s.
For example, the amplitude of the voltage oscillations in order to
increase the ionization rate of gas atoms can be in the range of
300 to 1000 V. The voltage oscillation duration can be in the range
of 3-8 microseconds. In an embodiment, only the RF power supply
1312 operates and the RF power level is optimized by adjusting
output power to provide an optimum amount of energy for the
electrons in order to provide a maximum probability to generate
atomic hydrogen when electrons collide with hydrogen molecules. In
an embodiment, power supplies 1312, 1313 operate simultaneously to
generate atomic hydrogen. The third step is the CVD film
deposition. In this case, any gas that includes carbon atoms, such
as acetylene, methane, and the like can be used. The substrate
temperature is in the range of 400 C.
[0241] In an embodiment, the workpiece is a part of a jet engine,
and the coating can be hydrogenated DLC, or hydrogenated
metal-doped DLC or Alpha Alumina.
[0242] In an embodiment, the magnetically enhanced CVD source can
be used to form hard DLC coating on the tip of the razor blade, as
shown in FIG. 30. A blade 1403 and magnetically enhanced CVD source
1401 are positioned inside the vacuum chamber 1406. A feed gas,
such as Ar, C2H2, CH4, or any other gas that contains carbon atoms
is used for the CVD process. Power supplies 1402 and/or 1407
release negative voltage pulses on the cathode target 1207 from the
magnetically enhanced CVD source. Power supply 1402 and/or 1407
control voltage amplitude, pulse duration, and frequency. The
parameters of the voltage pulses are shown in FIGS. 25 (a, b, c,
d), FIGS. 26 (a, b, c, d), FIGS. 27 (a, b, c, d). Power supply 1404
provides negative bias voltage on the blade in the range of -20 V
to -200V. Power supply 1408 is connected to pole piece 1214. Power
supply provides voltage pulses in order to increase electron energy
and increase ionization degree of carbon atoms. The voltage pulse
shapes and frequency are optimized in order to get DLC film with a
hardness in the range of 20-50 GPa. Typical voltage pulse amplitude
will be in the range of 1000-2000 V in order to obtain film
hardness in the range of 30 GPa. In some embodiments, cathode
target 1207 is inductively grounded. In some embodiments, pole
piece 1214 is inductively grounded.
[0243] The magnetically enhanced CVD source can be used for many
different applications. The application of diamond and DLC coatings
deposited with the CVD source includes but is not limited to smart
phones, tablets, flat panel displays, hard drives, read/write
heads, hair removal, optical filters, watches, valves, facets, thin
film batteries, disks, microelectronics, hard masks, transistors,
and/or manufacturing mono and polycrystalline substrates.
[0244] The magnetically enhanced CVD source can be used for
sputtering applications and can be used for chemically enhanced
ionized vapor deposition. The magnetically enhanced CVD source can
be configured as an Arc source.
[0245] A magnetically enhanced HDP-CVD plasma source includes a
hollow cathode target and an anode. The anode and cathode form a
gap. A cathode target magnet assembly forms magnetic field lines
that are substantially perpendicular to a cathode target surface.
The gap magnet assembly forms a cusp magnetic field in the gap that
is coupled with the cathode target magnetic field. The magnetic
field lines cross a pole piece and are shielded by a shield from
the plasma positioned between the poles and the gap. This pole
piece can be connected with a voltage power supply. The shield
piece can have a negative, positive, or floating electric
potential. The plasma source can be configured to generate volume
discharge. The gap size prohibits generation of plasma discharge in
the gap. By controlling the duration, value and a sign of the
electric potential on the pole piece, the plasma ionization can be
controlled. The magnetically enhanced HDP-CVD source can also be
used for chemically enhanced ionized physical vapor deposition
(CE-IPVD), plasma enhanced tomic layer deposition (PE-ALD) and
reactive ion etch (RIE) and plasma thrusters or pulsed plasma
thrusters (PPT). Gas flows through the gap between hollow cathode
and anode. The cathode target is inductively grounded, and the
substrate is periodically inductively grounded.
[0246] An embodiment of a magnetically enhanced CVD deposition
source magnetic field geometry is shown in FIGS. 31-32, and 36.
This geometry, on one side, forms a cusp magnetic field in a gap
between an anode and a hollow cathode target and, on another side,
forms magnetic field lines that cross a surface of the cathode
substantially perpendicular to the cathode surface. Therefore,
magnetic field lines from one side terminate on the cathode target
surface, and from another side the magnetic field lines terminate
in the gap on the shield 1131 that does not have the same potential
as a cathode target, and the shield piece 1131 is shielding the
pole piece 1106, 1109 from the plasma. This magnetic field geometry
does not confine secondary electrons near the cathode target
surface, as in conventional magnetron sputtering sources. Rather,
this magnetic field geometry allows secondary electrons to move
from the target surface toward the gap between the cathode and the
anode.
[0247] A magnetically enhanced CVD source includes a hollow cathode
target and at least two rows of magnets 1101, 1102, as shown in
FIGS. 31, 32, 36. The two rows of magnets face each other and
provide a magnetic field in the same direction (i.e., south-south
or north-north) and, therefore, generate cusp magnetic field
geometry 1103 in the gap 1113 between the hollow cathode target 104
and the anode 11105 where the anode is positioned on top of the
hollow cathode target 1104. A pole piece 1106 is disposed between
two rows of the magnets 1101, 1102. This pole piece 1106 can be
made from magnetic or nonmagnetic material. If the pole piece 1106
is made from magnetic material, the pole piece 1106 concentrates
the cusp magnetic field, which can increase a magnetic mirror
effect for the electrons drifting from the cathode target surface
towards the gap. There is another pole piece 1109 positioned on top
of the top row of magnets 1101. This pole piece 1109 is made from
magnetic material. The pole piece 1109 is not exposed to plasma
through the gap 1110 positioned in the anode 1105 because shield
1131 is protecting all the poles. The shield can be connected to
power supply 1107 or can be grounded or isolated from ground.
[0248] In some embodiments, power supply 1107 is an RF power
supply. In some embodiments, shield piece 1131 is grounded through
inductor 1127 to eliminate the DC bias. Magnetic field lines from
the bottom row of the magnets 1102 penetrate the top surface of the
hollow cathode target 1104 at a substantially 90-degree angle.
Magnetic field lines 1112 from the top row of the magnets terminate
on the magnetic shield piece 1131. Magnetic field lines 1111 from
the bottom row of magnet 1102 crosses over the magnetic pole pieces
1114, 1115, magnet 1116, and cathode target 1104. Pole pieces 114,
115 are made from magnetic material. Magnet 116 enhances the
magnetic field near the cathode target surface. The cathode target
104 is connected to multiple RF power supplies 118 with matching
network 1128 and optional common exciter 1140. The cathode target
1104 can be also connected to a regulated high power unipolar
voltage pulse power supply 1130 and pulse forming network (PFN)
1129 to produce a resonance asymmetric pulse AC discharge
superimposed over RF discharge. In some embodiments only two RF
power supplies 1118 are connected to the cathode target 1104 as
seen in FIG. 32. The power supplies 1118 can run in pulsed mode or
continuous mode. The power supplies 1118 can be at the same
frequency or different frequencies. Each frequency is chosen
carefully to optimize the ionization process for each element. For
example, a carbon atom has a different ionization potential than a
metal atom. The same applies to the ionization of gas molecules as
well.
[0249] In some embodiments, only a regulated high-power unipolar
voltage pulse power supply 1130 and pulse forming network (PFN)
1129 are used to produce a resonance asymmetric pulse AC discharge
when connected to the cathode target 1104 as shown in FIG. 36. In
some embodiments, an accelerating grid 1132 is positioned parallel
to the surface of the hollow cathode target, and a power supply
1133 is connected to the accelerating grid providing voltage for
ion acceleration from the magnetically enhanced chemical vapor
deposition (CVD) plasma source. In some embodiments, the power
supply 1133 can be operated in continuous or pulsed mode. In some
embodiments, the accelerating grid can be grounded. In some
embodiments, the shield 1131 can be grounded. In some embodiments,
a ground 1125 can be connected to the cathode target 1104 through
inductor 1124 and switch 1126. If the cathode target 1104 is
inductively grounded, the RF discharge cannot generate a constant
negative voltage bias. In this case, there is no sputtering from
the cathode target 1104. The switch 1126 can be synchronized in
pulse mode to turn on only when at least one RF generator is
pulsing and off when it is not. The switching frequency 1126 can be
synchronized with the pulsing of the power supply 1130, 1129.
[0250] An embodiment of a magnetically enhanced CVD deposition
source magnetic field geometry is shown in FIGS. 31, 32, 36. This
geometry, on one side, forms a cusp magnetic field in a gap between
an anode and a hollow cathode target and, on another side, forms
magnetic field lines that cross a surface of the cathode
substantially perpendicular to the cathode surface. Therefore,
magnetic field lines from one side terminate on the cathode target
surface, and from another side, the magnetic field lines terminate
in the gap on the shield 1131 that does not have the same potential
as a cathode target, and the shield piece 1131 shields the pole
piece 1106, 1109 from the plasma. This magnetic field geometry does
not confine secondary electrons near the cathode target surface, as
in conventional magnetron sputtering sources. Rather, this magnetic
field geometry allows secondary electrons to move from the target
surface toward the gap between the cathode and the anode.
[0251] A magnetically enhanced CVD source has a hollow cathode
target and at least two rows of magnets 1101 and 1102 as shown in
FIGS. 31, 32, and 36. The two rows of magnets face each other and
provide a magnetic field in the same direction (i.e., south-south
or north-north) and, therefore, generate cusp magnetic field
geometry 1103 in the gap 1113 between the hollow cathode target
1104 and the anode 1105 where the anode is positioned on top of the
hollow cathode target 1104. A pole piece 1106 is disposed between
two rows of the magnets 1101, 1102. This pole piece 1106 can be
made from magnetic or nonmagnetic material. If the pole piece 1106
is made from magnetic material, the pole piece 1106 concentrates
the cusp magnetic field, which can increase a magnetic mirror
effect for the electrons drifting from the cathode target surface
towards the gap. There is another pole piece 1109 positioned on top
of the top row of magnets 1101. This pole piece 1109 is made from
magnetic material. The pole piece 1109 is not exposed to plasma
through the gap 1110 positioned in the anode 1105 because shield
1131 protects all the poles pieces 1106, 1109 and magnets 1101,
1102. The shield can be connected to power supply 107 or can be
grounded or isolated from ground.
[0252] In some embodiments, power supply 1107 is an RF power
supply. In some embodiments, shield piece 1131 is grounded through
inductor 1127 to eliminate the DC bias. Magnetic field lines from
the bottom row of the magnets 1102 penetrate the top surface of the
hollow cathode target 1104 at a substantially 90-degree angle.
Magnetic field lines 1112 from the top row of the magnets terminate
on the magnetic shield piece 1131. Magnetic field lines 1111 from
the bottom row of magnet 1102 crosses over the magnetic pole pieces
1114, 1115, ring magnet 1116, and cathode target 1104. Another
magnetic assembly 1134, 1135 is positioned concentrically to the
ring magnet 1116 in a magnetron configuration on the cathode target
1104. Pole pieces 1114, 1115 are made from magnetic material.
Magnet 1116 enhances the magnetic field near the cathode target
surface. The cathode target 1104 is connected to multiple RF power
supplies 1118 with matching network 1128 and optional common
exciter 1140. The cathode target 1104 can be also connected to a
regulated high-power unipolar voltage pulse power supply 1130 and
pulse forming network (PFN) 1129 to produce a resonance asymmetric
pulse AC discharge superimposed over RF discharge as shown in FIG.
34. In some embodiments, only two RF power supplies 1118 are
connected to the cathode target 1104 as shown in FIG. 33. The power
supplies 1118 can run in pulsed mode or continuous mode. The power
supplies 1118 can be set to the same frequency or different
frequencies. Each frequency is chosen carefully to optimize the
ionization process for each element. For example, a carbon atom has
a different ionization potential than a metal atom. The same
applies to the ionization of gas molecules as well. In some
embodiments, a regulated high power unipolar voltage pulse power
supply 130 and pulse forming network (PFN) 1129 are used to produce
a resonance asymmetric pulse AC discharge when connected to the
cathode target 1104 as shown in FIG. 35. In some embodiments, an
accelerating grid 1132 positioned parallel to the surface of the
hollow cathode target and a power supply 1133 are connected to the
accelerating grid providing voltage for ion acceleration from the
magnetically enhanced chemical vapor deposition (CVD) plasma source
as shown in FIGS. 31, 32, 36. In some embodiments, the voltage
power supply 1133 can be operated in continuous or pulsed mode. In
some embodiments, the accelerating grid can be grounded. In some
embodiments, the shield 1131 can be grounded. In some embodiments,
a ground 1125 can be connected to the cathode target 1104 through
inductor 1124 and switch 1126. If the cathode target 1104 is
inductively grounded, the RF discharge cannot generate a constant
negative voltage bias. In this case, there is no sputtering from
the cathode target 1104. The switch 1126 can be synchronized in
pulse mode to turn on only when at least one RF generator is
pulsing and off when it is not. The switching frequency 1126 can be
synchronized with the pulsing of the power supply 1130, 1129.
[0253] An embodiment of a magnetically enhanced CVD deposition
source with hybrid magnetic field geometry is shown in FIGS. 33,
34, 35. This geometry, on one side, forms a cusp magnetic field in
a gap between an anode and a hollow cathode target and, on another
side, forms magnetic field lines that cross a surface of the
cathode substantially perpendicular to the cathode surface.
Therefore, magnetic field lines from one side terminate on the
cathode target surface, and from another side, the magnetic field
lines terminate in the gap on the shield 1131 that does not have
the same potential as a cathode target, and the shield piece 1131
shields the pole piece 1106, 1109 from the plasma. Adding a
magnetic assembly 1134, 1135 forms a magnetron configuration
concentric to pole piece 1115 and magnet 1116 that forms a closed
magnetic field on the surface of the cathode target 1104. Some of
the magnetic field on magnet 1134 couples to pole piece 1115 and
some of the magnetic field on magnet 1135 couples to the cusp field
on pole piece 1106. This hybrid magnetic field geometry does not
confine secondary electrons near the cathode target surface, as in
conventional magnetron sputtering sources, through the gap allowing
secondary electrons to move from the target surface toward the gap
between the cathode and the anode to break down the gas and improve
the ionization of the sputtered material from the inner concentric
magnetic field, which forms a magnetron configuration on the
surface of the target 1104 to cause sputtering from the cathode
target 1104 forming a layer of the substrate.
[0254] A magnetically enhanced CVD source includes a hollow cathode
target and at least two rows of magnets 1101, 1102 as shown in
FIGS. 34, 35, 36. The two rows of magnets face each other and
provide a magnetic field in the same direction (i.e., south-south
or north-north) and, therefore, generate cusp magnetic field
geometry 1103 in the gap 1113 between the hollow cathode target
1104 and the anode 1105, wherein the anode is positioned on top of
the hollow cathode target 1104. A pole piece 1106 is disposed
between two rows of the magnets 1101, 1102. This pole piece 1106
can be made from magnetic or nonmagnetic material. If the pole
piece 1106 is made from magnetic material, the pole piece 1106
concentrates the cusp magnetic field, which can increase a magnetic
mirror effect for the electrons drifting from the cathode target
surface towards the gap. There is another pole piece 1109
positioned on top of the top row of magnets 1101. This pole piece
1109 is made from magnetic material. The pole piece 1109 is not
exposed to plasma through the gap 1110 positioned in the anode 1105
because shield 1131 protects the poles pieces 1106, 1109 and
magnets 1101, 1102. The shield is connected to power supply 107,
grounded, or isolated from ground.
[0255] In some embodiments, power supply 1107 is an RF power
supply. In some embodiments, shield piece 1131 is grounded through
inductor 1127 to eliminate the DC bias. Magnetic field lines from
the bottom row of the magnets 1102 penetrate the top surface of the
hollow cathode target 1104 at a substantially 90-degree angle.
Magnetic field lines 1112 from the top row of the magnets terminate
on the magnetic shield piece 1131. Magnetic field lines 1111 from
the bottom row of magnet 1102 cross over the magnetic pole pieces
1114, 1115, ring magnet 1116, and cathode target 1104. Another
magnetic assembly 1134, 1135 is positioned concentrically to the
ring magnet 1116 in a magnetron configuration on the cathode target
1104. Some of the magnetic field on magnet 1134 couples to pole
piece 1115 and some of the magnetic field on magnet 1135 couples to
the cusp field on pole piece 1106. In some embodiments, magnet 1134
includes a one-ring magnet, wherein multiple shaped magnets form a
ring magnet, or an electromagnet ring. In some embodiments, magnet
1135 includes a single cylindrical magnet, wherein multiple shaped
ring magnets form a cylinder or an electromagnet. The concentric
magnetic assembly can be stationary or rotating. Pole pieces 1114,
1115 are made from magnetic material. Magnet 1116 enhances the
magnetic field near the cathode target surface. The cathode target
1104 is connected to multiple RF power supplies 1118 with matching
network 1128 and optional common exciter 1140. The cathode target
1104 can be also connected to a regulated high-power unipolar
voltage pulse power supply 1130 and pulse forming network (PFN)
1129 to produce a resonance asymmetric pulse AC discharge
superimposed over RF discharge as shown in FIG. 34. In some
embodiments, only two RF power supplies 1118 are connected to the
cathode target 1104, as shown in FIG. 33. The power supplies 1118
can run in pulsed mode or continuous mode. The power supplies 1118
can be set to the same frequency or different frequencies. Each
frequency is selected to optimize the ionization process for each
element. For example, a carbon atom has a different ionization
potential than a metal atom. The same applies to the ionization of
gas molecules as well. In some embodiments, a regulated high-power
unipolar voltage pulse power supply 130 and pulse forming network
(PFN) 1129 are used to produce a resonance asymmetric pulse AC
discharge when connected to the cathode target 1104 as shown in
FIG. 35. In some embodiments, an accelerating grid 1132 positioned
parallel to the surface of the hollow cathode target and a power
supply 1133 are connected to the accelerating grid providing
voltage for ion acceleration from the magnetically enhanced
chemical vapor deposition (CVD) plasma source, as shown in FIGS.
33, 34, 35. In some embodiments, the voltage power supply 1133 can
be operated in continuous or pulsed mode. In some embodiments, the
accelerating grid can be grounded. In some embodiments, the shield
1131 can be grounded. In some embodiments, a ground 1125 can be
connected to the cathode target 1104 through inductor 1124 and
switch 1126. If the cathode target 1104 is inductively grounded,
the RF discharge cannot generate a constant negative voltage bias.
In this case, there is no sputtering from the cathode target 1104.
The switch 1126 can be synchronized in pulse mode to turn on only
when at least one RF generator is pulsing and off when at least one
RF generator is not pulsing. The switching frequency 1126 can be
synchronized with the pulsing of the power supply 1130, 1129.
[0256] FIG. 37 shows continuous and pulsed RF voltages with varying
pulsed power, respectively, that can be provided by two power
supplies 1118. The RF power can be in the range of 100 W-50 kW. The
RF frequency can be in the range of 100 kHz-100 MHz. The frequency
of RF pulses can be in the range of 100 Hz-100 kHz.
[0257] FIG. 38 shows continuous and pulsed RF voltages with pulsed
power, respectively, that can be provided by two power supplies
1118. The RF power can be in the range of 100 W-50 kW. The RF
frequency can be in the range of 100 kHz-100 MHz. The frequency of
RF pulses can be in the range of 100 Hz-100 kHz.
[0258] FIG. 39 shows continuous and pulsed RF voltages with varying
pulsed power, respectively, that can be provided by two power
supplies 1118 superimposed with resonance asymmetric varying AC
pulse from a high-power pulse generator feeding a PFN connected to
the magnetically enhanced source. The RF power can be in the range
of 100 W-50 kW. The RF frequency can be in the range of 100 kHz-100
MHz. The frequency of RF pulses can be in the range of 100 Hz-100
kHz. The resonance asymmetric varying AC pulse is generated by a
high-power regulated unipolar negative voltage pulse generator 1130
feeding a PFN 1129 with a plurality of inductors and capacitors
tuned to generate a resonance effect on the magnetically enhanced
source as shown in FIGS. 31, 34. The resonance asymmetric varying
AC pulse can be synchronized with the pulsed RF generator 1118 or
not. The resonance asymmetric varying AC pulse can be in the range
of 0.1-20 KW/cm2, the frequency can be in the range of 1 Hz-100
KHz, the negative voltage can be in the range of -50 to -5000V and
the positive voltage can be in the range of 10 to 5000V. The pulse
width of the unipolar voltage pulse feeding the PFN can be in the
range of 0.1-1000 microseconds. The arc suppression can be
triggered by either generators 1118 or 130 as the master trigger
and the other supply can be in slave mode until the arc is
cleared.
[0259] FIG. 40 shows pulsed RF voltages with varying pulsed power
on a magnetically enhanced device as shown in FIGS. 32, 33, that
can be provided by one power supply 118. The RF power can be in the
range of 100 W-50 kW. The RF frequency can be in the range of 100
kHz-100 MHz. The frequency of RF pulses can be in the range of 100
Hz-100 kHz. Either source can have the cathode target 104 connected
to an inductor 1124 to ground 1125 through a switch. When connected
to ground, the RF generator 1118 cannot generate a DC voltage bias
on the target.
[0260] FIG. 41 shows pulsed RF voltages with varying pulsed power
on a magnetically enhanced device as shown in FIGS. 32, 33 that can
be provided by multiple power supplies 1118. The RF power can be in
the range of 100 W-50 kW. The RF frequency can be in the range of
100 kHz-100 MHz. The frequency of RF pulses can be in the range of
100 Hz-100 kHz. Either source can have the cathode target 1104
connected to an inductor 1124 to ground 1125 through a switch. When
connected to ground, the RF generator 1118 cannot generate a DC
voltage bias on the target.
[0261] FIG. 42 shows continuous and pulsed RF voltages with varying
pulsed power, respectively, that can be provided by two power
supplies 1118 superimposed with resonance asymmetric varying AC
pulses from a high-power pulse generator feeding a PFN connected to
the magnetically enhanced source. The RF power can be in the range
of 100 W-50 kW. The RF frequency can be in the range of 100 kHz-100
MHz. The frequency of RF pulses can be in the range of 100 Hz-100
kHz. The resonance asymmetric AC pulse is generated by a high-power
regulated unipolar negative voltage pulse generator 1130 feeding a
PFN 1129 with a plurality of inductors and capacitors tuned to
generate a resonance effect on the magnetically enhanced source as
shown in FIGS. 32, 34. The resonance asymmetric AC pulse can be
synchronized with the pulsed RF generator 1118 or not. The
resonance asymmetric varying AC pulse can be in the range of 0.1-20
KW/cm2, the frequency can be in the range of 1 Hz-100 KHz, the
negative voltage can be in the range of -50 to -5000V, and the
positive voltage can be in the range of 10-5000V. The pulse width
of the unipolar voltage pulse feeding the PFN can be in the range
of 0.1-1000 microseconds. The arc suppression can be triggered by
either generators 1118, 1130 as the master trigger, and the other
supply will be in slave mode until the arc is cleared. In some
embodiments, the superimposed resonance asymmetric AC pulse can be
a resonance symmetric AC pulse.
[0262] FIG. 43 shows continuous RF voltages with varying power on a
magnetically enhanced device as shown in FIGS. 32, 33,
respectively, which can be provided by two power supplies 118. The
RF power can be in the range of 100 W-50 kW. The RF frequency can
be in the range of 100 kHz-100 MHz. The frequency of RF pulses can
be in the range of 100 Hz-100 kHz. The generators can run at
different frequencies from each other. In some embodiments, the
common exciter (CEX) 1140 is used to prevent unwanted beat
frequencies. Two RF generators can be phase-locked together so that
the generators run at the same frequency and with a fixed phase
relationship between their outputs. This locking ensures repeatable
RF characteristics within the plasma.
[0263] FIG. 44 shows continuous and pulsed resonance asymmetric AC
pulses generated by a high-power regulated unipolar negative
voltage pulse generator 1130 feeding a PFN 1129 with a plurality of
inductors and capacitors tuned to generate a resonance effect on
the magnetically enhanced source as shown in FIGS. 35, 36. The
resonance asymmetric varying AC pulse can be in the range of 0.1-20
KW/cm2, the frequency is in the range of 1 Hz-100 KHz, the negative
voltage is in the range of -50 to -5000V, and the positive voltage
is in the range of 10 to 5000V. The pulse width of the unipolar
voltage pulse feeding the PFN can be in the range of 0.1-1000
microseconds. In some embodiments, the superimposed resonance
asymmetric AC pulse can be resonance symmetric AC pulse.
[0264] FIG. 45 show continuous and pulsed resonance asymmetric AC
pulses with multiple voltage peaks generated by a high-power
regulated unipolar negative voltage pulse generator 1130 feeding a
PFN 1129 with a plurality of inductors and capacitors tuned to
generate a resonance effect on the magnetically enhanced source as
shown in FIGS. 35, 36. The resonance asymmetric varying AC pulse
can be in the range of 0.1-20 KW/cm2, the frequency in the range of
1 Hz-100 KHz, the negative voltage can be in the range of -50 to
-5000V, and the positive voltage can be in the range of 10 to
5000V. The pulse width of the unipolar voltage pulse feeding the
PFN can be in the range of 0.1-1000 microseconds. In some
embodiments, the superimposed resonance asymmetric AC pulse can be
resonance symmetric AC pulses.
[0265] FIG. 46 show continuous and pulsed RF voltages with varying
pulsed power, respectively, that can be provided by two power
supplies 1118 superimposed with resonance asymmetric varying AC
pulses from a high-power pulse generator feeding a PFN connected to
the magnetically enhanced source. The RF power can be in the range
of 100 W-50 kW. The RF frequency can be in the range of 100 kHz-100
MHz. The frequency of RF pulses can be in the range of 100 Hz-100
kHz. The resonance asymmetric AC pulse is being generated by a high
power regulated unipolar negative voltage pulse generator 1130
feeding a PFN 1129 with a plurality of inductors and capacitors
tuned to generate a resonance effect on the magnetically enhanced
source as shown in FIGS. 31, 34 be have a single voltage and
multiple voltage peaks on the negative part of the AC cycle. The
resonance asymmetric AC pulse can be synchronized with the pulsed
RF generator 1118 or not. The resonance asymmetric varying AC pulse
can be in the range of 0.1-20 KW/cm2, the frequency in the range of
1 Hz-100 KHz, the negative voltage range can be in the range of 50
to 5000V, and the positive voltage can be in the range of 10 to
5000V. The pulse width of the unipolar voltage pulse feeding the
PFN can be in the range of 0.1-1000 microseconds. The arc
suppression can be triggered by either generators 1118, 1130 as the
master trigger and the other supply will be in slave mode until the
arc is cleared. In some embodiments, the superimposed resonance
asymmetric AC pulse can be resonance symmetric AC pulse.
[0266] FIG. 47 (a) shows input unipolar negative pulses applied to
a PFN 1129 connected to the magnetically enhanced source as shown
in FIGS. 35, 36 and the output high-power negative DC pulse of the
PFN 1129 on the magnetically enhanced source as shown in FIGS. 35,
36. The high-power negative DC pulse is generated by a multiple
high-power regulated unipolar negative voltage pulse generator 130
feeding a PFN 1129 with a plurality of inductors and capacitors
tuned to generate a DC voltage output. The DC pulse can be in the
range of 0.1-20 KW/cm2, the frequency in the range of 1 Hz-100 KHz,
and the negative voltage in the range of -50 to -5000V. The pulse
width of the unipolar voltage pulse feeding the PFN can be in the
range of 0.1-1000 microseconds and the output pulse of the PFN 1129
can be in the range 50 to 50000 microseconds.
[0267] FIG. 47 (b) shows input unipolar negative pulses to a PFN or
PCN 1129 connected to the magnetically enhanced source as shown in
FIGS. 35, 36 and output high-power oscillatory negative DC pulses
of the PFN or PCN 1129 on the magnetically enhanced source as shown
in FIGS. 35, 36. The high-power oscillatory negative DC pulse is
generated by a multiple high-power regulated unipolar negative
voltage pulse generator 1130 feeding a PFN or PCN 1129 with a
plurality of inductors and capacitors tuned to generate a DC
voltage output. The oscillatory DC pulse can be in the range of
0.1-20 KW/cm2, the frequency in the range of 1 Hz-100 KHz, and the
negative voltage in the range of -50 to 5000V. The pulse width of
the unipolar voltage pulse feeding the PFN can be in the range of
0.1-1000 microseconds and the output pulse of the PFN or PCN can be
in the range 50-50000 microseconds. The oscillation on the
oscillatory DC pulse can be +/-99% of the input unipolar negative
pulse values.
[0268] FIG. 47 (c) shows input unipolar negative pulses to a PFN or
PCN 1129 connected to the magnetically enhanced source as shown in
FIGS. 35, 36 and the output pulsed resonance asymmetric AC pulse
generated by a high-power regulated unipolar negative voltage pulse
generator 1130 feeding a PFN or PCN 1129 with a plurality of
inductors and capacitors tuned to generate a resonance effect on
the magnetically enhanced source as shown in FIGS. 35, 36. The
resonance asymmetric varying AC pulse can be in the range of 0.1-20
KW/cm2, the frequency in the range of 1 Hz-100 KHz, the negative
voltage can be in the range of 50-5000V, and the positive voltage
can be in the range of 10-5000V. The pulse width of the unipolar
voltage pulse feeding the PFN or PCN 1129 can be in the range of
0.1-1000 microseconds. In some embodiments, the superimposed
resonance asymmetric AC pulse can be a resonance symmetric AC
pulse.
[0269] FIG. 48 (a) show the components of a high-power pulse
generator 1130, which utilizes high-power regulated voltage source
1135 charging a pulse generator 1136 with programmable pulse
frequency, pulse width, and voltage level. The pulse generator 1136
produces negative unipolar voltage pulses feeding a second PFN or
pulse converter network (PCN) 1129 with a plurality of inductors
and capacitors arranged in a configuration with values to produce a
desired pulsed output on the magnetically enhanced source 1137. In
some embodiments, the pulse generator 1136 can have an isolated
output utilizing a transformer and a full-wave diode bridge feeding
a built in PFN to adjust voltage rise-time and fall-time. The
output from the isolated pulse voltage generator feeds the second
PFN or PCN 1129, which is connected to the magnetically enhanced
source 1137. In some embodiments, the magnetically enhanced source
1137 can be configured as shown in FIG. 36, in which the magnetic
field directly coupled to the cusp field through the gap 1103, or
FIG. 35, in which the magnetic field is directly coupled to the
cusp field through the gap 1103 and an inner magnetic assembly
forming a magnetron configuration on the cathode target 1104. In
some embodiments, a portion of the magnetic field 1111 can couple
with the magnetic field 1112. In some embodiments, an arc
suppression circuit 1134 can be included. A voltage probe 1138 and
current sensor 1141 are coupled between the second PFN or PCN 1129
and the magnetically enhanced source 1137 to measure voltage and
current on the magnetically enhanced source 1137. These measurement
signals are ultimately fed to the microcontroller circuit 1139,
which is controlled by a computer 1140. The data from these sensors
can be used to determine peak pulse values and average value of
either voltage or current. Peak power and average power can be
calculated. The sensors can be used for over-voltage and
over-current protection. The high-power pulse generator 1130 can be
programmed to run in continuous mode or pulsed burst mode to
prevent the cathode 1104 from thermal damage. The pulsed burst mode
can be programmed to have a varying unipolar voltage level forcing
the second PFN or PCN 1129 to produce a varying resonance pulse
output on the magnetically enhanced source 1137, thereby generating
high density plasma that is inductively current driven. The
resonance asymmetric varying AC pulse can be in the range of about
0.1-20 KW/cm2, the frequency in the range of about 1 Hz-100 KHz,
the negative voltage in the range of about -50 to -5000V, and the
positive voltage in the range of about 10 to 5000V. The pulse width
of the unipolar voltage pulse feeding the PFN can be in the range
of about 0.1-1000 microseconds, and the unipolar voltage pulse
level can be in the range of about -50 to 4000V. In some
embodiments, the superimposed resonance asymmetric AC pulse can be
a resonance symmetric AC pulse with variable peak voltage
levels.
[0270] FIG. 48 (b, c) show the input unipolar negative voltage
pulses to a PFN 1129 connected to the magnetically enhanced source
as shown in FIGS. 35, 36 with variable voltage levels in two
different bursts f4 and f5. V7<V8 and the output pulsed
resonance asymmetric AC pulse is generated by a high-power
regulated unipolar negative voltage pulse generator 1130 feeding
the PFN 1129 with a plurality of inductors and capacitors tuned to
generate a resonance effect on the magnetically enhanced source as
shown in FIGS. 35, 36 with variable peak voltage levels. The
resonance asymmetric varying AC pulse can be in the range of 0.1-20
KW/cm2, the frequency in the range of 1 Hz-100 KHz, the negative
voltage in the range of -50 to -5000V, and the positive voltage in
the range of 10 to 5000V. The pulse width of the unipolar voltage
pulse feeding the PFN can be in the range of 0.1-1000 microseconds
and the unipolar voltage pulse level can be in the range of -50 to
-4000V. In some embodiments, the superimposed resonance asymmetric
AC pulse can be a resonance symmetric AC pulse with variable peak
voltage levels.
[0271] One or more embodiments disclosed herein, or a portion
thereof, may make use of software running on a computer or
workstation. By way of example, only and without limitation, FIG. 7
is a block diagram of an embodiment of a machine in the form of a
computing system 900, within which is a set of instructions 902
that, when executed, cause the machine to perform any one or more
of the methodologies according to embodiments of the invention. In
one or more embodiments, the machine operates as a standalone
device; in one or more other embodiments, the machine is connected
(e.g., via a network 922) to other machines. In a networked
implementation, the machine operates in the capacity of a server or
a client user machine in a server-client user network environment.
Exemplary implementations of the machine as contemplated by
embodiments of the invention include, but are not limited to, a
server computer, client user computer, personal computer (PC),
tablet PC, personal digital assistant (PDA), cellular telephone,
mobile device, palmtop computer, laptop computer, desktop computer,
communication device, personal trusted device, web appliance,
network router, switch or bridge, or any machine capable of
executing a set of instructions (sequential or otherwise) that
specify actions to be taken by that machine.
[0272] The computing system 900 includes a processing device(s) 904
(e.g., a central processing unit (CPU), a graphics processing unit
(GPU), or both), program memory device(s) 906, and data memory
device(s) 908, which communicate with each other via a bus 910. The
computing system 900 further includes display device(s) 912 (e.g.,
liquid crystal display (LCD), flat panel, solid state display, or
cathode ray tube (CRT)). The computing system 900 includes input
device(s) 914 (e.g., a keyboard), cursor control device(s) 916
(e.g., a mouse), disk drive unit(s) 918, signal generation
device(s) 920 (e.g., a speaker or remote control), and network
interface device(s) 924, operatively coupled together, and/or with
other functional blocks, via bus 910.
[0273] The disk drive unit(s) 918 includes machine-readable
medium(s) 926, on which is stored one or more sets of instructions
902 (e.g., software) embodying any one or more of the methodologies
or functions herein, including those methods illustrated herein.
The instructions 902 may also reside, completely or at least
partially, within the program memory device(s) 906, the data memory
device(s) 908, and/or the processing device(s) 904 during execution
thereof by the computing system 900. The program memory device(s)
906 and the processing device(s) 904 also constitute
machine-readable media. Dedicated hardware implementations, such as
but not limited to ASICs, programmable logic arrays, and other
hardware devices can likewise be constructed to implement methods
described herein. Applications that include the apparatus and
systems of various embodiments broadly comprise a variety of
electronic and computer systems. Some embodiments implement
functions in two or more specific interconnected hardware modules
or devices with related control and data signals communicated
between and through the modules, or as portions of an ASIC. Thus,
the example system is applicable to software, firmware, and/or
hardware implementations.
[0274] The term "processing device" as used herein is intended to
include any processor, such as, for example, one that includes a
CPU (central processing unit) and/or other forms of processing
circuitry. Further, the term "processing device" may refer to more
than one individual processor. The term "memory" is intended to
include memory associated with a processor or CPU, such as, for
example, RAM (random access memory), ROM (read only memory), a
fixed memory device (for example, hard drive), a removable memory
device (for example, diskette), a flash memory and the like. In
addition, the display device(s) 912, input device(s) 914, cursor
control device(s) 916, signal generation device(s) 920, etc., can
be collectively referred to as an "input/output interface," and is
intended to include one or more mechanisms for inputting data to
the processing device(s) 904, and one or more mechanisms for
providing results associated with the processing device(s).
Input/output or I/O devices (including but not limited to keyboards
(e.g., alpha-numeric input device(s) 914, display device(s) 912,
and the like) can be coupled to the system either directly (such as
via bus 910) or through intervening input/output controllers
(omitted for clarity).
[0275] In an integrated circuit implementation of one or more
embodiments of the invention, multiple identical die are typically
fabricated in a repeated pattern on a surface of a semiconductor
wafer. Each such die may include a device described herein, and may
include other structures and/or circuits. The individual dies are
cut or diced from the wafer, then packaged as integrated circuits.
One skilled in the art would know how to dice wafers and package
die to produce integrated circuits. Any of the exemplary circuits
or method illustrated in the accompanying figures, or portions
thereof, may be part of an integrated circuit. Integrated circuits
so manufactured are considered part of this invention.
[0276] An integrated circuit in accordance with the embodiments of
the present invention can be employed in essentially any
application and/or electronic system in which buffers are utilized.
Suitable systems for implementing one or more embodiments of the
invention include, but are not limited, to personal computers,
interface devices (e.g., interface networks, high-speed memory
interfaces (e.g., DDR3, DDR4), etc.), data storage systems (e.g.,
RAID system), data servers, etc. Systems incorporating such
integrated circuits are considered part of embodiments of the
invention. Given the teachings provided herein, one of ordinary
skill in the art will be able to contemplate other implementations
and applications.
[0277] In accordance with various embodiments, the methods,
functions or logic described herein is implemented as one or more
software programs running on a computer processor. Dedicated
hardware implementations including, but not limited to, application
specific integrated circuits, programmable logic arrays and other
hardware devices can likewise be constructed to implement the
methods described herein. Further, alternative software
implementations including, but not limited to, distributed
processing or component/object distributed processing, parallel
processing, or virtual machine processing can also be constructed
to implement the methods, functions or logic described herein.
[0278] The embodiment contemplates a machine-readable medium or
computer-readable medium containing instructions 902, or that which
receives and executes instructions 902 from a propagated signal so
that a device connected to a network environment 922 can send or
receive voice, video or data, and to communicate over the network
922 using the instructions 902. The instructions 902 are further
transmitted or received over the network 922 via the network
interface device(s) 924. The machine-readable medium also contains
a data structure for storing data useful in providing a functional
relationship between the data and a machine or computer in an
illustrative embodiment of the systems and methods herein.
[0279] While the machine-readable medium 902 is shown in an example
embodiment to be a single medium, the term "machine-readable
medium" should be taken to include a single medium or multiple
media (e.g., a centralized or distributed database, and/or
associated caches and servers) that store the one or more sets of
instructions. The term "machine-readable medium" shall also be
taken to include any medium that is capable of storing, encoding,
or carrying a set of instructions for execution by the machine and
that cause the machine to perform anyone or more of the
methodologies of the embodiment. The term "machine-readable medium"
shall accordingly be taken to include, but not be limited to:
solid-state memory (e.g., solid-state drive (SSD), flash memory,
etc.); read-only memory (ROM), or other non-volatile memory; random
access memory (RAM), or other re-writable (volatile) memory;
magneto-optical or optical medium, such as a disk or tape; and/or a
digital file attachment to e-mail or other self-contained
information archive or set of archives is considered a distribution
medium equivalent to a tangible storage medium. Accordingly, the
embodiment is considered to include anyone or more of a tangible
machine-readable medium or a tangible distribution medium, as
listed herein and including art-recognized equivalents and
successor media, in which the software implementations herein are
stored.
[0280] It should also be noted that software, which implements the
methods, functions and/or logic herein, are optionally stored on a
tangible storage medium, such as: a magnetic medium, such as a disk
or tape; a magneto-optical or optical medium, such as a disk; or a
solid-state medium, such as a memory automobile or other package
that houses one or more read-only (non-volatile) memories, random
access memories, or other re-writable (volatile) memories. A
digital file attachment to e-mail or other self-contained
information archive or set of archives is considered a distribution
medium equivalent to a tangible storage medium. Accordingly, the
disclosure is considered to include a tangible storage medium or
distribution medium as listed herein and other equivalents and
successor media, in which the software implementations herein are
stored.
[0281] Although the specification describes components and
functions implemented in the embodiments with reference to
particular standards and protocols, the embodiments are not limited
to such standards and protocols.
[0282] The illustrations of embodiments described herein are
intended to provide a general understanding of the structure of
various embodiments, and they are not intended to serve as a
complete description of all the elements and features of apparatus
and systems that might make use of the structures described herein.
Many other embodiments will be apparent to those of skill in the
art upon reviewing the above description. Other embodiments are
utilized and derived therefrom, such that structural and logical
substitutions and changes are made without departing from the scope
of this disclosure. Figures are also merely representational and
are not drawn to scale. Certain proportions thereof are
exaggerated, while others are decreased. Accordingly, the
specification and drawings are to be regarded in an illustrative
rather than a restrictive sense.
[0283] Such embodiments are referred to herein, individually and/or
collectively, by the term "embodiment" merely for convenience and
without intending to voluntarily limit the scope of this
application to any single embodiment or inventive concept if more
than one is in fact shown. Thus, although specific embodiments have
been illustrated and described herein, it should be appreciated
that any arrangement calculated to achieve the same purpose are
substituted for the specific embodiments shown. This disclosure is
intended to cover any and all adaptations or variations of various
embodiments. Combinations of the above embodiments, and other
embodiments not specifically described herein, will be apparent to
those of skill in the art upon reviewing the above description.
[0284] In the foregoing description of the embodiments, various
features are grouped together in a single embodiment for the
purpose of streamlining the disclosure. This method of disclosure
is not to be interpreted as reflecting that the claimed embodiments
have more features than are expressly recited in each claim.
Rather, as the following claims reflect, inventive subject matter
lies in less than all features of a single embodiment. Thus, the
following claims are hereby incorporated into the detailed
description, with each claim standing on its own as a separate
example embodiment.
[0285] The abstract is provided to comply with 37 C.F.R. .sctn.
1.72(b), which requires an abstract that will allow the reader to
quickly ascertain the nature of the technical disclosure. It is
submitted with the understanding that it will not be used to
interpret or limit the scope or meaning of the claims. In addition,
in the foregoing Detailed Description, it can be seen that various
features are grouped together in a single embodiment for the
purpose of streamlining the disclosure. This method of disclosure
is not to be interpreted as reflecting an intention that the
claimed embodiments require more features than are expressly
recited in each claim. Rather, as the following claims reflect,
inventive subject matter lies in less than all features of a single
embodiment. Thus, the following claims are hereby incorporated into
the Detailed Description, with each claim standing on its own as
separately claimed subject matter.
[0286] Although specific example embodiments have been described,
it will be evident that various modifications and changes are made
to these embodiments without departing from the broader scope of
the inventive subject matter described herein. Accordingly, the
specification and drawings are to be regarded in an illustrative
rather than a restrictive sense. The accompanying drawings that
form a part hereof, show by way of illustration, and without
limitation, specific embodiments in which the subject matter are
practiced. The embodiments illustrated are described in sufficient
detail to enable those skilled in the art to practice the teachings
herein. Other embodiments are utilized and derived therefrom, such
that structural and logical substitutions and changes are made
without departing from the scope of this disclosure. This Detailed
Description, therefore, is not to be taken in a limiting sense, and
the scope of various embodiments is defined only by the appended
claims, along with the full range of equivalents to which such
claims are entitled.
[0287] Given the teachings provided herein, one of ordinary skill
in the art will be able to contemplate other implementations and
applications of the techniques of the disclosed embodiments.
Although illustrative embodiments have been described herein with
reference to the accompanying drawings, it is to be understood that
these embodiments are not limited to the disclosed embodiments, and
that various other changes and modifications are made therein by
one skilled in the art without departing from the scope of the
appended claims.
* * * * *