U.S. patent application number 10/989975 was filed with the patent office on 2006-05-18 for erosion resistant textured chamber surface.
This patent application is currently assigned to Applied Materials, Inc.. Invention is credited to Karl Brueckner, Alan Popiolkowski, Marc O'Donnell Schweitzer, Jennifer Watia Tiller, Brian T. West.
Application Number | 20060105182 10/989975 |
Document ID | / |
Family ID | 36386706 |
Filed Date | 2006-05-18 |
United States Patent
Application |
20060105182 |
Kind Code |
A1 |
Brueckner; Karl ; et
al. |
May 18, 2006 |
Erosion resistant textured chamber surface
Abstract
A component for a substrate processing chamber has a structure
having an overlying metal coating. The metal coating has a
plurality of electron beam textured features that are formed by
scanning an electron beam across a surface of the metal coating.
The electron beam textured features include a plurality of
depressions and protuberances on the surface that are capable of
accumulating process deposits during processing of a substrate to
reduce contamination of the substrate. The component having the
metal coating provides improved processing results, and exhibits
reduced erosion during cleaning processes performed to remove
process deposits from the component.
Inventors: |
Brueckner; Karl; (Santa
Clara, CA) ; West; Brian T.; (San Jose, CA) ;
Schweitzer; Marc O'Donnell; (San Jose, CA) ; Tiller;
Jennifer Watia; (Santa Clara, CA) ; Popiolkowski;
Alan; (Los Banos, CA) |
Correspondence
Address: |
APPLIED MATERIALS, INC.;Patent Department, M/S 2061
P.O. Box 450A
Santa Clara
CA
95052
US
|
Assignee: |
Applied Materials, Inc.
|
Family ID: |
36386706 |
Appl. No.: |
10/989975 |
Filed: |
November 16, 2004 |
Current U.S.
Class: |
428/457 ;
428/98 |
Current CPC
Class: |
C23C 16/4404 20130101;
H01J 37/32862 20130101; H01J 37/32504 20130101; Y10T 428/24
20150115; C23C 14/564 20130101; H01L 21/6875 20130101; H01J
37/32871 20130101; H01J 37/16 20130101; H01J 2237/022 20130101;
H01L 21/68757 20130101; Y10T 428/31678 20150401 |
Class at
Publication: |
428/457 ;
428/098 |
International
Class: |
B32B 5/00 20060101
B32B005/00; B32B 15/04 20060101 B32B015/04 |
Claims
1. A component for a substrate processing chamber, the component
comprising: (a) a component structure; (b) a metal coating on the
component structure; and (c) electron beam textured features on the
metal coating, the electron beam textured features comprising a
plurality of depressions and protuberances, whereby the component
provides improved erosion resistance in the substrate processing
chamber.
2. A component according to claim 1 wherein the metal coating
comprises at least one of stainless steel, copper, nickel, tantalum
and titanium.
3. A component according to claim 2 wherein the metal coating
comprises a sprayed coating that is formed by at least partially
melting coating material and propelling the coating material onto
the component structure.
4. A component according to claim 1 wherein the metal coating has a
thickness of from about 120 micrometers to about 2600
micrometers.
5. A component according to claim 1 wherein the electron beam
textured features comprise depressions having (i) a depth of from
about 20 micrometers to about 1600 micrometers, and (ii) a surface
diameter of from about 120 micrometers to about 2600 micrometers,
and protuberances comprising a height of from about 50 micrometers
to about 1600 micrometers.
6. A component according to claim 1 wherein the component comprises
at least one of a chamber enclosure wall, a chamber shield, a
target, a target rim, a cover ring, a deposition ring, a support
ring, an insulator ring, a coil, a coil support, a shutter disk, a
clamp shield, and a portion of a substrate support.
7. A substrate processing chamber comprising the component of claim
1, the chamber comprising a substrate support, gas delivery system,
gas energizer and exhaust.
8. A process kit for a substrate processing chamber, the process
kit comprising: (a) a ring adapted to at least partially surround a
substrate in the processing chamber, the ring comprising a metallic
material; (b) a stainless steel coating on the ring; and (c)
electron beam textured features on the stainless steel coating, the
electron beam textured features comprising a plurality of
depressions and protuberances, whereby the process kit provides
improved erosion resistance in the substrate processing
chamber.
9. A component according to claim 8 wherein the electron beam
textured features comprise depressions having (i) a depth of from
about 20 micrometers to about 1600 micrometers, and (ii) a surface
diameter of from about 120 micrometers to about 2600 micrometers,
and protuberances comprising a height of from about 50 micrometers
to about 1600 micrometers.
10. A component according to claim 8 wherein the ring comprises a
metallic material comprising at least one of titanium, stainless
steel, copper, tantalum and aluminum.
11. A process chamber shield for a substrate processing chamber,
the shield comprising: (a) a shield structure adapted to at least
partially shield a process chamber wall, the shield structure
comprising a metallic material; (b) a stainless steel coating on
the shield structure; and (c) electron beam textured features on
the stainless steel coating, the electron beam textured features
comprising a plurality of depressions and protuberances, whereby
the process chamber shield provides improved erosion resistance in
the substrate processing chamber.
12. A component according to claim 11 wherein the electron beam
textured features comprise depressions having (i) a depth of from
about 20 micrometers to about 1600 micrometers, and (ii) a surface
diameter of from about 120 micrometers to about 2600 micrometers,
and protuberances comprising a height of from about 50 micrometers
to about 1600 micrometers.
13. A component according to claim 11 wherein the shield structure
comprises a metallic material comprising at least one of titanium,
stainless steel, copper, tantalum and aluminum.
14. A method of fabricating a component for a substrate processing
chamber, the method comprising: (a) providing a component
structure; (b) forming a metal coating on the component structure,
the metal coating having a surface; and (c) scanning an electron
beam across the surface to form a plurality of electron beam
textured features comprising depressions and protuberances in the
surface.
15. A method according to claim 14 wherein (b) comprises forming a
metal coating comprising at least one of stainless steel, copper,
nickel, tantalum and titanium.
16. A method according to claim 14 wherein (b) comprises spraying a
metal coating on the component structure by at least partially
melting coating material and propelling the coating material onto
the structure.
17. A method according to claim 14 wherein (b) comprises forming a
metal coating having a thickness of from about 120 micrometers to
about 2600 micrometers.
18. A method according to claim 14 wherein (c) comprises scanning
an electron beam across the surface to form a plurality of electron
beam textured features comprising depressions having (i) a depth of
from about 20 micrometers to about 1600 micrometers, and (ii) a
surface diameter of from about 120 micrometers to about 2600
micrometers, and protuberances having a height of from about 50
micrometers to about 1600 micrometers.
Description
BACKGROUND
[0001] In the processing of substrates such as semiconductor wafers
and displays, a substrate is placed in a process chamber and
exposed to an energized gas to deposit or etch material on the
substrate. During such processing, process residues are generated
and can deposit on internal surfaces in the chamber. For example,
in sputter deposition processes, material sputtered from a target
for deposition on a substrate also deposits on other component
surfaces in the chamber, such as on deposition rings, shadow rings,
wall liners, and focus rings. In subsequent process cycles, the
deposited process residues can "flake off" of the chamber surfaces
to fall upon and contaminate the substrate. To reduce the
contamination of the substrates by process residues, the surfaces
of components in the chamber can be textured. Process residues
adhere to the textured surface and inhibit the process residues
from falling off and contaminating the substrates in the
chamber.
[0002] In one version, the textured component surface is formed by
directing an electromagnetic energy beam onto a surface of a
process chamber component surface to form depressions and
protrusions to which process deposits adhere. An example of such a
surface is a Lavacoat.TM. surface, as described for example in U.S.
Patent Publication No. 2003-0173526 to Popiolkowski et al,
published on Sep. 18, 2003, and filed on Mar. 13, 2002; and U.S.
Patent Publication No. 2004-0056211 to Popiolkowski et al,
published on Mar. 25, 2004, and filed on Jul. 17, 2003--both
commonly assigned to Applied Materials, Inc, and both of which are
incorporated herein by reference in their entireties. The
Lavacoat.TM. surface comprises depressions and protrusions to which
process residues can adhere to reduce the contamination of
substrates during their processing.
[0003] While components having textured surfaces provide improved
residue adherence over other types of process components,
performance issues can arise when the components are cleaned to
remove accumulated process residues. In an exemplary cleaning
process, the component comprising the textured surface is immersed
in a cleaning solution, such as an acidic solution. However,
cleaning solutions that are capable of cleaning process residues
can also erode the textured surface to alter the surface features,
and consequently, reduce the adherence of process residues thereto.
For example, textured component surfaces comprising aluminum and
titanium can be eroded by an acidic solution of HNO.sub.3 and
HF--which is used to remove tantalum-containing process residues
from the component surfaces. Because the eroded surfaces can
exhibit poor residue adhesion, the components may require
replacement or refurbishment after only a few cleaning cycles,
thereby increasing substrate processing costs and chamber
downtime.
[0004] Accordingly, it is desirable to have a component comprising
a textured surface that provides good adherence of process
residues, to improve processing results and reduce contamination of
substrates. It is further desirable to be able to effectively clean
accumulated process residues from the component surface without
erosion of the residues during cleaning. It is further desirable to
have a method of fabricating a component having a textured surface
that has improved erosion resistance during cleaning processes and
provides good results in the processing of substrates.
SUMMARY
[0005] In one version, a component for a substrate processing
chamber has a structure having an overlying metal coating. The
metal coating has a plurality of electron beam textured features
that are formed by scanning an electron beam across a surface of
the metal coating. The textured features include a plurality of
depressions and protuberances that are capable of accumulating
process deposits during processing of a substrate to reduce
contamination of the substrate. The component having the metal
coating provides improved processing results, and exhibits reduced
erosion during cleaning processes performed to remove process
deposits from the component.
[0006] In another version, a process kit for a substrate processing
chamber has a ring adapted to at least partially surround a
substrate in the processing chamber. The ring is of a metallic
material, and has a stainless steel coating. The stainless steel
coating has electron beam textured features thereon, the electron
beam textured features having a plurality of depressions and
protuberances. The process kit provides improved erosion resistance
in the substrate processing chamber.
[0007] In yet another version, a process chamber shield for a
substrate processing chamber has a shield structure that is adapted
to at least partially shield a process chamber wall. The shield
structure is of a metallic material, and has a stainless steel
coating. The stainless steel coating has electron beam textured
features thereon, the electron beam textured features having a
plurality of depressions and protuberances. The process chamber
shield provides improved erosion resistance in the substrate
processing chamber.
[0008] In another version, a method of fabricating a component for
a substrate processing chamber includes providing a component
structure and forming a metal coating on the component structure.
An electron beam is scanned across a surface of the metal coating
to form a plurality of textured features including depressions and
protuberances on the surface. The metal coating can be formed by at
least partially melting a coating material and propelling the
coating material onto the component structure.
DRAWINGS
[0009] These features, aspects, and advantages of the present
invention will become better understood with regard to the
following description, appended claims, and accompanying drawings,
which illustrate examples of the invention. However, it is to be
understood that each of the features can be used in the invention
in general, not merely in the context of the particular drawings,
and the invention includes any combination of these features,
where:
[0010] FIG. 1a is a sectional side view of a component having a
metal coating and a textured surface formed by scanning an
electromagnetic energy beam across the layer;
[0011] FIG. 1b is a sectional top view of an embodiment of the
component of FIG. 1a; and
[0012] FIG. 2 is a sectional side view of an embodiment of a
substrate processing chamber having one or more components
comprising electron beam textured features on a metal coating.
DESCRIPTION
[0013] A process chamber component 22 having a textured surface 20
is provided for the processing of substrates in an energized gas in
a process chamber 106, as shown for example in FIGS. 1a and 1b. The
component 22 having the textured surface reduces particle
generation in the process chamber 106 by providing a "sticky"
surface to which process deposits 24 adhere, thus allowing the
deposits 24 to accumulate on the textured surface 20. Process
deposits 24 that adhere to the textured surface 20 can include
metal-containing deposits, such as deposits comprising at least one
of tantalum, tantalum nitride, titanium, titanium nitride,
aluminum, copper, tungsten, and tungsten nitride. The chamber
components 22 having the textured surface 20 can comprise, for
example, a portion of a gas delivery system 112 that provides
process gas in the chamber 106, a substrate support 114 that
supports the substrate 104a in the chamber 106, a process kit 139,
a gas energizer 116 that energizes the process gas, chamber
enclosure walls 118 and shields 120, or a gas exhaust 122 that
exhausts gas from the chamber 106.
[0014] Referring to FIG. 2, which illustrates an exemplary version
of a physical vapor deposition chamber 106, components 22 having
the textured surface 20 can include a chamber enclosure wall 118, a
chamber shield 120, a target 124, a target rim 125, a component of
a process kit 139 such as at least one of a cover ring 126 and a
deposition ring 128, a support ring 130, insulator ring 132, a coil
135, coil support 137, shutter disk 104b, clamp shield 141, and a
portion of the substrate support 114. For example, components
having the textured surface can include Applied Material's part
numbers 0020-50007, 0020-50008, 0020-50010, 0020-50012, 0020-50013,
0020-48908, 0021-23852, 0020-48998, 0020-52149, 0020-51483,
0020-49977, 0020-52151, 0020-48999, 0020-48042 and 0190-14818, from
Applied Materials, Santa Clara, Calif. This list of components is
merely exemplary and the other components or components from other
types of chambers can also have the textured surface, thus, the
present invention should not be limited to the components listed or
described herein.
[0015] In one version, one or more process chamber components 22
comprise a surface that is textured by scanning an electromagnetic
energy beam 40 such as an electron beam 40 across the surface 20,
to form electron beam textured features 25 on the surface. An
example of such a textured surface 20 is that formed by a
Lavacoat.TM. process, as described for example in U.S. patent
application Ser. No. 10/653,713 to West, et al, filed on Sep. 2,
2003, entitled "Fabricating and Cleaning Chamber Components Having
Textured Surfaces," and aforementioned U.S. Patent Publication Nos.
2003/0173526 and 2004/0056211, all commonly assigned to Applied
Materials, Inc., and all of which are incorporated herein by
reference in their entireties. The electron beam textured features
25 of the Lavacoat.TM. process comprise a plurality of depressions
23 and protuberances 26 to which process deposits 24 generated
during processing can adhere, as shown for example in FIG. 1a.
[0016] The Lavacoat.TM. textured surface 20 can be formed by
generating an electromagnetic energy beam 40, such as an electron
beam 40, and directing the beam onto the surface 20 of the
component 22. While the electromagnetic energy beam is preferably
an electron beam, it can also comprise protons, neutrons and X-rays
and the like. The beam 40 is typically focused on a region of the
surface 20 for a period of time, during which time the beam 40
interacts with the surface 20 to form the textured features 25 on
the surface 20. It is believed that the beam 40 forms the features
25 by rapidly heating the region of the surface 20, typically to a
melting temperature of the surface material. At least a portion of
the surface material may even be evaporated or ablated from the
surface 20 by the rapid heating. The rapid heating causes some of
the surface material to be ejected outwards, which forms
depressions 23 in the regions the material was ejected from, and
protuberances 26 in areas where the ejected material re-deposits.
After the desired features in the region are formed, the beam 40 is
scanned to a different region of the component surface 20 to form
features in the new region.
[0017] The electromagnetic energy beam 40 can be scanned across the
surface 20 to form a desired pattern of textured features 25 on the
surface 20, such as a honeycomb-like structure of depressions 23
and protuberances 26, as shown for example in FIG. 1a. The features
25 formed by this method are typically macroscopically sized. For
example, the depressions 23 can have a depth d as measured from a
base level 28 of the surface 20 of from about 20 micrometers to
about 1600 micrometers. A surface diameter w of the depressions 23
may be from about 120 micrometers to about 2600 micrometers and
even from about 200 micrometers to about 2300 micrometers. The
protuberances 26 can comprise a height h above the base surface 28
of from about 50 micrometers to about 1600 micrometers, and even
from about 100 micrometers to about 1200 micrometers. The
Lavacoat.TM. textured surface 20 can have an overall surface
roughness average of from about 60 micrometers to about 100
micrometers, the roughness average of the surface 20 being defined
as the mean of the absolute values of the displacements from the
mean line of the features along the surface 20. The textured
surface 20 can also be further roughened after scanning with the
electromagnetic energy beam 40 to provide different levels of
texture on the surface 20, as described for example in the patent
applications to Popiolkowski et al. and West et al. that are
incorporated by reference above. For example, the surface 20 can be
grit blasted by propelling grit particles towards the surface 20
with pressurized gas, or can be chemically roughened, to form a
relatively fine texture overlying the macroscopically sized
features 25 on the surface 20. The roughened surface 20 improves
the adhesion of process deposits 24 to reduce contamination of the
processed substrates 104a.
[0018] In one version, the textured surface 20 can be formed on a
metal coating 30 on the component 22, as shown for example in FIG.
1a. The metal coating 30 desirably comprises a material that is
resistant to erosion by the energized gases provided to process a
substrate 104a or clean the process chamber 106, and is also
desirably resistant to erosion from cleaning solutions that may be
used to clean the component 20, such as acidic or basic cleaning
solutions. The metal coating 30 can be formed on a surface 33 of an
underlying structure 32 of the component 30 to protect the
underlying structure 32. For example, the underlying structure 32
may comprise a first material having desired properties, such as
desired thermal and mechanical properties, and the metal coating 30
may comprise a second material having higher erosion resistance
than the first material. The metal coating 30 may also comprise a
material that can be treated to provide a desired texture of the
metal coating surface, such as for example a desired roughness or
textured pattern on the surface 20, that could not otherwise be
desirably provided by the material of the underlying structure 32.
For example, the material of the metal coating may be selected to
allow for a finer or rougher texturing of the metal coating surface
20. A suitable material for the metal coating 30 can be selected
with respect to the substrate processing requirements to provide
the desired properties, and can comprise for example at least one
of stainless steel, copper, nickel, tantalum and titanium.
[0019] A material having suitable properties for the underlying
structure 32 may be a metallic material, such as for example at
least one of titanium, stainless steel; copper, tantalum and
aluminum; and can also comprise a ceramic material, such as at
least one of aluminum oxide, aluminum nitride, and quartz. The
underlying structure is selected according to desired properties
such as desired thermal and mechanical properties. For example, an
underlying structure 32 comprising aluminum may be desirable
because aluminum is typically a relatively cheap material having
good thermal conductivity. An underlying structure 32 comprising
stainless steel may provide good erosion resistance and thermal
conductivity. An underlying structure 32 comprising titanium may
provide a desired relatively low thermal coefficient of expansion.
Also, an underlying structure 32 comprising copper may provide good
thermal conductivity as well as a relatively low thermal
coefficient of expansion. Underlying structures 32 comprising a
ceramic material, such as aluminum oxide, may provide a desired
level of thermal insulation and/or thermal conductivity, and a
desired relatively low thermal coefficient of expansion. In one
suitable embodiment, a metal coating 30 comprising stainless steel
is formed over an underlying structure 32 comprising aluminum or
titanium, such as a process kit or shield structure, to provide a
component 22 having a textured surface 20 with improved erosion
resistance while maintaining the desired overall mechanical and
thermal properties of the component 22. In another suitable
embodiment, a metal coating 30 comprising stainless steel is formed
over an underlying structure 32 comprising aluminum oxide.
[0020] In one version, the metal coating 30 can be providing by
spraying a coating of material over the surface 33 of the
underlying component structure 32. Suitable spraying methods can
include thermal spraying methods, such as for example at least one
of HVOF (high velocity oxygen fuel), flame spraying, plasma
spraying, twin wire or single wire arc spraying, welding methods
such as TIG, and other thermal spraying methods, which are capable
of forming well-bonded coatings. In a typical thermal spraying
method, the coating material in powder or wire form is heated to a
molten or near-molten state, for example by a torch. A pressurized
gas is used to propel the coating material onto the surface 33 of
the underlying structure 32. For example, in the HVOF method, an
HVOF spray gun ignites an oxygen-fuel mixture to heat and at least
partially melt the coating material as it is propelled towards the
structure surface 33. A HVOF spray gun that may be suitable for
forming the metal coating 30 is the HVOF spray gun available from
Sulzer Metco Holding AG in Winterthur, Switzerland. Alternatively,
the metal coating 30 can be formed by other methods, such as by
electroplating metal coating material on the underlying structure
32, or by a physical or chemical vapor deposition method.
[0021] The metal coating 30 desirably comprises a thickness that is
sufficiently high to provide good erosion resistance and allow for
the formation of the textured features 25 on the surface 20 of the
coating 30. The metal coating 30 is desirably also sufficiently
thin to provide good adhesion of the coating 30 to the underlying
structure 32 to inhibit spalling or flaking of the coating 30 from
the structure. A suitable thickness may be a thickness of the metal
coating 30 may from about 120 micrometers to about 2600
micrometers, such as from about 500 micrometers to about 1300
micrometers. The metal coating 30 can be formed over substantially
the entire surface 33 of the underlying structure 32, or on
selected portions of the structure surface 33 that are, for
example, especially susceptible to erosion, or that tend to
accumulate large quantities of process deposits 24. Once the metal
coating 30 has been formed, the coating 30 can be textured, for
example by scanning an electron beam 40 across the surface 20 of
the coating 30, to form the textured features 25 that are capable
of collecting process deposits during the processing of substrates
104a. The textured features 25 are desirably formed substantially
entirely in the metal coating 30, and substantially without
exposing the underlying structure 32, as shown for example in FIG.
1a.
[0022] The component 22 comprising the metal coating 30 having the
textured surface 20 can be cleaned after processing a predetermined
number of substrates 104a to remove process deposits 24 that have
accumulated on the textured surface 20, such as tantalum-containing
deposits. For example, the textured surface 20 of the component 22
can be immersed in a cleaning solution, such as an acidic solution
of 20% by weight HF and 80% by weight HNO.sub.3, to clean the
process deposits 24. Any exposed regions of the surface 33 of the
underlying structure 32 that are not covered by the metal coating
30 can be masked with a protective material, such as a
polyester-based material, to protect the regions from erosion by
the cleaning solution. An example of a protective material may be
polyester tape (plater's tape) commercially available from 3M.TM.,
United States. Other cleaning solutions and steps may also be
provided, such as rinsing with de-ionized water, ultrasonicating,
baking or immersing in other chemical cleaning solutions.
[0023] The component 22 having the metal coating 30 with the
textured surface 20 provides improved results over components 22
without the metal coating 30. For example, a component 22 having a
metal coating 30 with an electron beam textured surface 20 that
comprises stainless steel, and that is formed over an underlying
structure 32 comprising aluminum or titanium, can be cleaned in a
cleaning solution comprising HF and HNO.sub.3 and recycled for
re-use in the process chamber 106 at least about 10 times, while
continuing to provide good processing results in the chamber 106.
In contrast, a component 22 without a metal coating 30, such as a
component 22 consisting of aluminum and having an electron beam
textured surface 20, is typically capable of being cleaned and
re-cycled for re-use in the process chamber 106 no more than about
3 times, before the erosion of the component 22 becomes too severe
to provide good processing results.
[0024] An example of a suitable process chamber 106 having a
component 22 with a metal coating 30 and electron beam textured
features 25 and is shown in FIG. 2. The chamber 106 can be a part
of a multi-chamber platform (not shown) having a cluster of
interconnected chambers connected by a robot arm mechanism that
transfers substrates 104a between the chambers 106. In the version
shown, the process chamber 106 comprises a sputter deposition
chamber, also called a physical vapor deposition or PVD chamber,
which is capable of sputter depositing material on a substrate
104a, such as one or more of tantalum, tantalum nitride, titanium,
titanium nitride, copper, tungsten, tungsten nitride and aluminum.
The chamber 106 comprises enclosure walls 118 that enclose a
process zone 109, and that include sidewalls 164, a bottom wall
166, and a ceiling 168. A support ring 130 can be arranged between
the sidewalls 164 and ceiling 168 to support the ceiling 168. Other
chamber walls can include one or more shields 120 that shield the
enclosure walls 118 from the sputtering environment.
[0025] The chamber 106 comprises a substrate support 114 to support
substrates 104a in the sputter deposition chamber 106. The
substrate support 114 may be electrically floating or may comprise
an electrode 170 that is biased by a power supply 172, such as an
RF power supply. The substrate support 114 can also support other
wafers 104 such as a moveable shutter disk 104b that can protect
the upper surface 134 of the support 114 when the substrate 104a is
not present. In operation, the substrate 104a is introduced into
the chamber 106 through a substrate loading inlet (not shown) in a
sidewall 164 of the chamber 106 and placed on the support 114. The
support 114 can be lifted or lowered by support lift bellows and a
lift finger assembly (not shown) can be used to lift and lower the
substrate onto the support 114 during transport of the substrate
104a into and out of the chamber 106.
[0026] The support 114 may also comprise a process kit 139 one or
more rings, such as a cover ring 126 and a deposition ring 128,
which cover at least a portion of the upper surface 134 of the
support 114 to inhibit erosion of the support 114. In one version,
the deposition ring 128 at least partially surrounds the substrate
104a to protect portions of the support 114 not covered by the
substrate 104a. The cover ring 126 encircles and covers at least a
portion of the deposition ring 128, and reduces the deposition of
particles onto both the deposition ring 128 and the underlying
support 114.
[0027] A process gas, such as a sputtering gas, is introduced into
the chamber 106 through a gas delivery system 112 that includes a
process gas supply comprising one or more gas sources 174 that each
feed a conduit 176 having a gas flow control valve 178, such as a
mass flow controller, to pass a set flow rate of the gas
therethrough. The conduits 176 can feed the gases to a mixing
manifold (not shown) in which the gases are mixed to from a desired
process gas composition. The mixing manifold feeds a gas
distributor 180 having one or more gas outlets 182 in the chamber
106. The process gas may comprise a non-reactive gas, such as argon
or xenon, which is capable of energetically impinging upon and
sputtering material from a target. The process gas may also
comprise a reactive gas, such as one or more of an
oxygen-containing gas and a nitrogen-containing gas, that are
capable of reacting with the sputtered material to form a layer on
the substrate 104a. Spent process gas and byproducts are exhausted
from the chamber 106 through an exhaust 122 which includes one or
more exhaust ports 184 that receive spent process gas and pass the
spent gas to an exhaust conduit 186 in which there is a throttle
valve 188 to control the pressure of the gas in the chamber 106.
The exhaust conduit 186 feeds one or more exhaust pumps 190.
Typically, the pressure of the sputtering gas in the chamber 106 is
set to sub-atmospheric levels.
[0028] The sputtering chamber 106 further comprises a sputtering
target 124 facing a surface 105 of the substrate 104a, and
comprising material to be sputtered onto the substrate 104a, such
as for example at least one of tantalum and tantalum nitride. The
target 124 is electrically isolated from the chamber 106 by an
annular insulator ring 132, and is connected to a power supply 192.
The sputtering chamber 106 also has a shield 120 to protect a wall
118 of the chamber 106 from sputtered material. The shield 120 can
comprise a wall-like cylindrical shape having upper and lower
shield sections 120a, 120b that shield the upper and lower regions
of the chamber 106. In the version shown in FIG. 2, the shield 120
has an upper section 120a mounted to the support ring 130 and a
lower section 120b that is fitted to the cover ring 126. A clamp
shield 141 comprising a clamping ring can also be provided to clamp
the upper and lower shield sections 120a,b together. Alternative
shield configurations, such as inner and outer shields, can also be
provided. In one version, one or more of the power supply 192,
target 124, and shield 120, operate as a gas energizer 116 that is
capable of energizing the sputtering gas to sputter material from
the target 124. The power supply 192 applies a bias voltage to the
target 124 with respect to the shield 120. The electric field
generated in the chamber 106 from the applied voltage energizes the
sputtering gas to form a plasma that energetically impinges upon
and bombards the target 124 to sputter material off the target 124
and onto the substrate 104a. The support 114 having the electrode
170 and support electrode power supply 172 may also operate as part
of the gas energizer 116 by energizing and accelerating ionized
material sputtered from the target 124 towards the substrate 104a.
Furthermore, a gas energizing coil 135 can be provided that is
powered by a power supply 192 and that is positioned within the
chamber 106 to provide enhanced energized gas characteristics, such
as improved energized gas density. The gas energizing coil 135 can
be supported by a coil support 137 that is attached to a shield 120
or other wall in the chamber 106.
[0029] The chamber 106 can be controlled by a controller 194 that
comprises program code having instruction sets to operate
components of the chamber 106 to process substrates 104a in the
chamber 106. For example, the controller 194 can comprise a
substrate positioning instruction set to operate one or more of the
substrate support 114 and substrate transport to position a
substrate 104a in the chamber 106; a gas flow control instruction
set to operate the flow control valves 178 to set a flow of
sputtering gas to the chamber 106; a gas pressure control
instruction set to operate the exhaust throttle valve 188 to
maintain a pressure in the chamber 106; a gas energizer control
instruction set to operate the gas energizer 116 to set a gas
energizing power level; a temperature control instruction set to
control temperatures in the chamber 106; and a process monitoring
instruction set to monitor the process in the chamber 106.
[0030] Although exemplary embodiments of the present invention are
shown and described, those of ordinary skill in the art may devise
other embodiments which incorporate the present invention, and
which are also within the scope of the present invention. For
example, the features 25 can be formed on the surface 20 by means
other than those specifically described. Also, the metal coating 30
may comprise materials other than those described, and may be
formed by alternative suitable methods. Furthermore, relative or
positional terms shown with respect to the exemplary embodiments
are interchangeable. Therefore, the appended claims should not be
limited to the descriptions of the preferred versions, materials,
or spatial arrangements described herein to illustrate the
invention.
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