U.S. patent application number 14/001315 was filed with the patent office on 2013-12-12 for arc evaporation source.
This patent application is currently assigned to Kabushiki Kaisha Kobe Seiko Sho (Kobe Steel, Ltd.). The applicant listed for this patent is Shinichi Tanifuji, Kenji Yamamoto. Invention is credited to Shinichi Tanifuji, Kenji Yamamoto.
Application Number | 20130327642 14/001315 |
Document ID | / |
Family ID | 49111783 |
Filed Date | 2013-12-12 |
United States Patent
Application |
20130327642 |
Kind Code |
A1 |
Tanifuji; Shinichi ; et
al. |
December 12, 2013 |
ARC EVAPORATION SOURCE
Abstract
An arc evaporation source (101) according to one embodiment of
the present invention comprises: a ring-shaped circumferential
magnet (103) which is so arranged as to surround the outer
circumference of a target (102) along a direction in which the
direction of magnetization becomes parallel with the front surface
of the target; and a rear surface magnet (104) which is arranged on
the rear surface side of the target (102) along a direction in
which the direction of magnetization becomes perpendicular to the
front surface of the target. The magnetic pole of the
circumferential magnet (103) on the inner side in the radial
direction and the magnetic pole of the rear surface magnet (104) on
the target (102) side have the same polarity as each other.
Inventors: |
Tanifuji; Shinichi;
(Kobe-shi, JP) ; Yamamoto; Kenji; (Kobe-shi,
JP) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
Tanifuji; Shinichi
Yamamoto; Kenji |
Kobe-shi
Kobe-shi |
|
JP
JP |
|
|
Assignee: |
Kabushiki Kaisha Kobe Seiko Sho
(Kobe Steel, Ltd.)
Kobe-shi
JP
|
Family ID: |
49111783 |
Appl. No.: |
14/001315 |
Filed: |
February 23, 2012 |
PCT Filed: |
February 23, 2012 |
PCT NO: |
PCT/JP12/54451 |
371 Date: |
August 23, 2013 |
Current U.S.
Class: |
204/298.41 |
Current CPC
Class: |
H01J 37/3452 20130101;
H01J 37/32055 20130101; H01J 37/32669 20130101; H01J 37/345
20130101; C23C 14/325 20130101; C23C 14/24 20130101; H01J 37/3402
20130101; H01J 37/34 20130101 |
Class at
Publication: |
204/298.41 |
International
Class: |
C23C 14/24 20060101
C23C014/24 |
Foreign Application Data
Date |
Code |
Application Number |
Feb 23, 2011 |
JP |
2011-037094 |
Feb 23, 2011 |
JP |
2011-037095 |
Apr 25, 2011 |
JP |
2011-097162 |
May 26, 2011 |
JP |
2011-118267 |
Aug 22, 2011 |
JP |
2011-180544 |
Claims
1. An arc evaporation source, comprising: at least one of a
ring-shaped circumferential magnet and a rear surface magnet,
wherein the ring-shaped circumferential magnet is disposed to an
outer circumference of a target, the rear surface magnet is
disposed at a back of the target, and one of the ring-shaped
circumferential magnet and the rear surface magnet is disposed so
as to have a polarity where a direction of magnetization is
parallel with a front surface of the target, by which a direction
of lines of magnetic force passing an evaporation surface of the
target becomes substantially vertical to the evaporation
surface.
2. The arc evaporation source according to claim 1, comprising: the
ring-shaped circumferential magnet and a ring-shaped magnetic field
generating mechanism, wherein the ring-shaped circumferential
magnet is disposed surrounding the outer circumference of the
target so as to have a polarity where the direction of
magnetization is parallel with the front surface of the target, and
the ring-shaped magnetic field generating mechanism is disposed
ahead of the target such that an axis of the ring-shaped magnetic
field generating mechanism is along a direction substantially
vertical to the front surface of the target, thereby generating a
magnetic field substantially vertical to the front surface of the
target.
3. The arc evaporation source according to claim 1, comprising: the
ring-shaped circumferential magnet and the rear surface magnet,
wherein the ring-shaped circumferential magnet is disposed
surrounding the outer circumference of the target so as to have a
polarity where the direction of magnetization is parallel with the
front surface of the target, the rear surface magnet is disposed
such that the direction of magnetization is along a direction
crossing the front surface of the target, and a magnetic pole of
the ring-shaped circumferential magnet in a radial inside of the
ring-shaped circumferential magnet and a magnetic pole of the rear
surface magnet on a side of the target have a polarity identical
with each other.
4. The arc evaporation source according to claim 1, comprising: the
ring-shaped circumferential magnet and the rear surface magnet,
wherein the rear surface magnet has a ring shape, the ring-shaped
circumferential magnet is disposed surrounding the outer
circumference of the target so as to have a polarity where the
direction of magnetization is along a direction crossing the front
surface of the target and directing ahead or behind, the rear
surface magnet has an inner diameter larger than a size of the
target and is disposed so as to have a polarity where the direction
of magnetization is parallel with the front surface of the target,
and a direction of magnetization of the rear surface magnet is
directed to a radial inside of the rear surface magnet when a
direction of magnetization of the ring-shaped circumferential
magnet is directed ahead, and the direction of magnetization of the
rear surface magnet is directed to a radial outside of the rear
surface magnet when the direction of magnetization of the
ring-shaped circumferential magnet is directed behind.
5. An arc evaporation source, comprising: a ring-shaped
circumferential magnet and a ring-shaped magnetic field generating
mechanism, wherein a direction of magnetization of the ring-shaped
circumferential magnet is along a radial direction, the ring-shaped
circumferential magnet is disposed surrounding an outer
circumference of a target such that the direction of magnetization
of the ring-shaped circumferential magnet is along a direction
parallel with a front surface of the target, and the ring-shaped
magnetic field generating mechanism is disposed ahead of the target
such that an axis of the ring-shaped magnetic field generating
mechanism is along a direction substantially vertical to the front
surface of the target, thereby generating a magnetic field
substantially vertical to the front surface of the target.
6. The arc evaporation source according to claim 5, wherein at
least one of a front end and a rear end of the ring-shaped
circumferential magnet is situated at a back of the front surface
of the target and ahead of a rear surface of the target.
7. An arc evaporation source, comprising: a ring-shaped
circumferential magnet and a ring-shaped magnetic field generating
mechanism, wherein a direction of magnetization of the ring-shaped
circumferential magnet is along a radial direction, the ring-shaped
circumferential magnet is disposed with a front end of the
ring-shaped circumferential magnet being situated at a hack of a
rear surface of a target such that the direction of magnetization
of the ring-shaped circumferential magnet is along a direction
parallel with a front surface of the target, and the ring-shaped
magnetic field generating mechanism is disposed ahead of the target
such that an axis of the ring-shaped magnetic field generating
mechanism is along a direction substantially vertical to the front
surface of the target, thereby generating a magnetic field in a
direction substantially vertical to the front surface of the
target.
8. The arc evaporation source according to claim 5, wherein the
target is in a disk-like shape and the ring-shaped circumferential
magnet is a permanent magnet.
9. An arc evaporation source, comprising: a ring-shaped
circumferential magnet and a rear surface magnet, wherein the
ring-shaped circumferential magnet is disposed surrounding an outer
circumference of a target such that a direction of magnetization of
the ring-shaped circumferential magnet is along a direction
parallel with a front surface of the target, the rear surface
magnet is disposed at a back of the target such that a direction of
magnetization of the rear surface magnet is along a direction
crossing the front surface of the target, and a magnetic pole in a
radial inside of the ring-shaped circumferential magnet and a
magnetic pole of the rear surface magnet on a target side have a
polarity identical with each other.
10. The arc evaporation source according to claim 9, wherein the
ring-shaped circumferential magnet is disposed such that a
projection shadow as viewed in a radial direction of the
ring-shaped circumferential magnet overlaps a projection shadow as
viewed in a radial direction of the target.
11. The arc evaporation source according to claim 9, wherein the
ring-shaped circumferential magnet is disposed such that an
intermediate position between a front end of the ring-shaped
circumferential magnet and a rear end of the ring-shaped
circumferential magnet is situated behind an intermediate position
between the front surface of the target and a rear surface of the
target.
12. The arc evaporation source according to claim 9, further
comprising: a ring-shaped magnetic field generating mechanism that
generates a magnetic field in a direction identical with that of
the rear surface magnet, wherein the ring-shaped magnetic field
generating mechanism is disposed ahead of the target so as to pass
lines of magnetic force that have passed the front surface of the
target from an inner circumferential surface of the ring-shaped
magnetic field generating mechanism to the radial inside.
13. The arc evaporation source according to claim 9, wherein the
ring-shaped magnetic field at the front surface of the target is
100 gauss or more.
14. An arc evaporation source comprising: a ring-shaped
circumferential magnet, a rear surface magnet, and a ring-shaped
magnetic field generating mechanism, wherein the ring-shaped
circumferential magnet is disposed at a back of a rear surface of a
target such that a direction of magnetization of the ring-shaped
circumferential magnet is along a direction parallel with a front
surface of the target, the rear surface magnet is disposed such
that a direction of magnetization of the rear surface magnet
crosses the front surface of the target, a magnetic pole in a
radial inside of the ring-shaped circumferential magnet and a
magnetic pole of the rear surface magnet on a target side have a
polarity identical with each other, and the ring-shaped magnetic
field generating mechanism is disposed ahead of the target so as to
generate a magnetic field in a direction identical with that of the
rear surface magnet and cause lines of magnetic force that have
passed the front surface of the target to pass the radial inside of
the ring-shaped magnetic field generating mechanism.
15. The arc evaporation source according to claim 5, wherein the
ring-shaped magnetic field generating mechanism comprises a
solenoid coil.
16. The arc evaporation source according to claim 9, wherein the
target is in a disk-like shape, the rear surface magnet comprises a
solenoid coil, and the ring-shaped circumferential magnet comprises
a permanent magnet.
17. An arc evaporation source comprising: a ring-shaped
circumferential magnet and a ring-shaped rear surface magnet,
wherein the ring-shaped circumferential magnet is disposed
surrounding an outer circumference of a target and has a polarity
where a direction of magnetization is along a direction crossing a
front surface of the target and directed ahead or behind, the
ring-shaped rear surface magnet is disposed at a back of the
target, has an inner diameter larger than that of the target, and
has a polarity where the direction of magnetization is parallel
with the front surface of the target, and a direction of
magnetization of the ring-shaped rear surface magnet is directed to
a radial inside of the ring-shaped rear surface magnet when a
direction of magnetization of the ring-shaped circumferential
magnet is directed ahead, and the direction of magnetization of the
ring-shaped rear surface magnet is directed to a radial outside of
the ring-shaped rear surface magnet when the direction of
magnetization of the ring-shaped circumferential magnet is directed
behind.
18. The arc evaporation source according to claim 17, wherein a
front end of the ring-shaped circumferential magnet is disposed so
as to be on a plane identical with the front surface of the target,
or ahead of the front surface of the target.
19. The arc evaporation source according to claim 17, wherein the
ring-shaped rear surface magnet has a ring-shaped first rear
surface magnet and a second rear surface magnet having a polarity
identical with a direction of magnetization of the ring-shaped
first rear surface magnet, and the second rear surface magnet is
disposed coaxially with the ring-shaped first rear surface magnet
at a back of the target and ahead or behind the ring-shaped first
rear surface magnet.
20. The arc evaporation source according to claim 19, wherein a
magnetic body that penetrates the ring-shaped first rear surface
magnet and the second rear surface magnet is disposed to the radial
inside of the ring-shaped first rear surface magnet and the second
rear surface magnet, and the ring-shaped circumferential surface of
the ring-shaped magnetic body is in contact with an inner
circumferential surface of the ring-shaped first rear surface
magnet and that of the second rear surface magnet.
21. The arc evaporation source according to claim 9, wherein the
target is in a disk-like shape and the rear surface magnet and the
ring-shaped circumferential magnet each comprise a permanent
magnet.
Description
TECHNICAL FIELD
[0001] The present invention relates to an arc evaporation source
used in a film deposition apparatus that forms a thin film such as
a ceramic film composed of a nitride or an oxide or an amorphous
carbon film for improving abrasion resistance or the like of
mechanical components, etc.
BACKGROUND ART
[0002] Heretofore, for the purpose of improving abrasion
resistance, sliding property, and protective function of mechanical
parts, cutting tools, or slidable parts, a physical vapor
deposition of coating the surface of substrates of the parts and
the tools with a thin film has been used generally. As the physical
vapor deposition, arc ion plating or sputtering has been known
generally. The arc ion plating is a technique of using a cathodic
arc evaporation source.
[0003] A cathode discharge arc evaporation source (hereinafter
referred to as an arc evaporation source) generates arc discharge
on the surface of a target as a cathode, and instantaneously melts
and evaporates the material constituting the target. In the arc
evaporation source, the material ionized by arc discharge is drawn
toward a substrate which is an object to be processed to form a
thin film on the surface of the substrate. According to the arc
evaporation source, since an evaporation rate of the target is high
and an ionization rate of the evaporated material is high, a dense
film can be formed by applying a bias to the substrate during film
deposition. Therefore, the arc evaporation source has been
industrially used for forming an abrasion resistant film on the
surface of the cutting tools, etc.
[0004] Atoms constituting the target which are evaporated by arc
discharge are highly dissociated electrolytically or ionized in arc
plasmas. In this case, transportation of ions from the target to
the substrate undergoes the effect of a magnetic field between the
target and the substrate, and the trajectory thereof is along lines
of magnetic force from the target to the substrate.
[0005] However, in arc discharge generated between a cathode
(target) and an anode, when the target is evaporated around
electron emission points (arc spots) on the cathode as the center,
a molten target before evaporation (macro-particles) are sometimes
emitted from the vicinity of the arc spots. Deposition of the
macro-particles to the object to be processed causes deterioration
of the surface roughness of the thin film.
[0006] In this regard, when the arc spots move at a high speed, the
amount of the macro-particles tends to be suppressed. The moving
speed of the arc spots undergoes the effect of a magnetic field
applied to the surface of the target.
[0007] In order to solve such a problem, the following techniques
of controlling the movement of the arc spots by application of a
magnetic field to the surface of the target have been proposed.
[0008] A Patent reference 1 discloses a vacuum arc evaporation
source of applying a vertical magnetic field to the surface of the
target by providing a ring-shaped magnetic field generating source
to the circumference of the target. It is described in the Patent
reference 1 that the moving speed of the arc spots is increased and
generation of the molten particles can be suppressed by the vacuum
arc evaporation source.
[0009] A Patent reference 2 discloses an arc evaporation source in
which a magnet is disposed at the back of the cathode.
[0010] A Patent reference 3 discloses an arc evaporation source
comprising an circumferential magnet surrounding the outer
circumference of a target and having a direction of magnetization
along the direction crossing the surface of the target, and a rear
surface magnet having a polarity in the direction identical with
that of the circumferential magnet and the direction of
magnetization along the direction crossing the surface of the
target. It is described in the Patent reference 3 that the
straightness of the lines of magnetic force can be improved by the
arc evaporation source.
[0011] A Patent reference 4 discloses an arc evaporation apparatus
forming a magnetic field parallel with the surface of a target by a
ring-shaped magnet disposed around the target and a solenoid coil
at the back thereof. It is described in the Patent reference 4 that
induction of arc in accordance with all of tracks from the center
to the outer edge of the target is attained according to the arc
evaporation apparatus.
CITATION LIST
Patent Literature
[0012] Patent reference 1: Japanese Patent Laid-Open No. H11-269634
[0013] Patent reference 2: Japanese Patent Laid-Open No. H08-199346
[0014] Patent reference 3: Japanese Patent Laid-Open No.
2010-275625 [0015] Patent reference 4: Japanese Patent Laid-Open
No. 2004-523658
SUMMARY OF THE INVENTION
Technical Problem
[0016] However, in the vacuum arc evaporation source disclosed in
the Patent reference 1, since the magnetic field is applied to the
surface of the target only from the circumference of the target,
the intensity of the magnetic field is decreased in the vicinity of
the center of a target surface. When discharge is performed in the
vicinity of the center where the intensity of the magnetic field is
decreased, a great amount of macro-particles are released.
[0017] It is difficult to apply the technique in which the magnetic
field is decreased in the vicinity of the center to an evaporation
source of using a large size target. Further, since the lines of
magnetic force from the surface of the target do not extend in the
direction to the substrate, the material of the target which is
ionized by evaporation cannot be induced efficiently to the
substrate. In order to avoid the problem, it may be considered to
increase the value of a current added to a ring-shaped magnetic
field generating source. However, the configuration of relying only
on the increase of the current is limited in view of the problem
such as generation of heat, etc.
[0018] Further, since the lines of magnetic force from the surface
of the target are directed in the direction deviating from the
axis, a great amount of lines of magnetic force deviating from the
substrate are generated. In the configuration of the magnetic field
where such lines of magnetic field are formed, since ions
evaporated from the target are not transported efficiently to the
substrate, the film deposition rate is lowered.
[0019] Further, according to the arc evaporation source disclosed
in the Patent reference 2, while a strong magnetic field can be
applied to the surface of the cathode by the magnet at the back of
the cathode, lines of magnetic force extend (diverge) in the
direction from the center to the outer circumference (outer side)
at the surface of the cathode. In a state where a vertical magnetic
field is applied to the surface of the cathode, arc spots tend to
move in the direction in which the lines of magnetic forces are
turned down. Accordingly, the arc spots move to the outer
circumference during discharge to cause instable discharge and,
concurrently, local discharge occurs only at the outer
circumference. Further, since the lines of magnetic force from the
target do not extend in the direction to the substrate, ionized
target material cannot be induced efficiently in the direction to
the substrate.
[0020] In the arc evaporation source disclosed in the Patent
reference 3, lines of magnetic force are generated in the direction
from the surface of the target to the substrate by two disk-shaped
magnets disposed being spaced from each other at the back of the
target, the two disk magnets can generate lines of magnetic force
at high straightness in a central region. However, lines of
magnetic force emitting from the outer circumference relative to
the central region diverge outwardly relative to the axis of the
disk magnets. Since this is an inevitable phenomenon as general
characteristics of magnets, there is still a room for improvement
in inducing the ionized target material efficiently to the
substrate.
[0021] Further, according to the arc evaporation apparatus
disclosed in the Patent reference 4, lines of magnetic force at
high straightness are generated from the central region of the
solenoid coil, but lines of magnetic force emitting from the outer
circumference relative to the central region of the solenoid coil
diverge outwardly relative to the axis of the solenoid coil.
[0022] That is, in the techniques disclosed in the Patent
references 3 and 4, lines of magnetic force of high straightness
can be generated only at the central region of the target from the
front of the target to the substrate in view of the characteristics
of permanent magnets or electromagnets disposed at the back of the
target. Accordingly, the film deposition rate cannot be improved
sufficiently even by the techniques disclosed in the Patent
references 3 and 4.
[0023] In view of the problems described above, the present
invention intends to provide an arc evaporation source capable of
controlling lines of magnetic force such that the slope of the
lines of magnetic force at the front of the target is vertical, or
the slope of the lines of magnetic force at the front of the target
is in a direction from the outer circumference to the center
(inside) at the front of the cathode.
Solution to Problem
[0024] For attaining the foregoing object, the arc evaporation
source according to the present invention includes
[0025] at least one of a ring-shaped circumferential magnet
disposed to the outer circumference of a target and a rear surface
magnet disposed at the back of the target in which
[0026] one of the circumferential magnet and the rear surface
magnet is disposed so as to have a polarity where the direction of
magnetization is parallel with the front surface of the target, by
which the direction of lines of magnetic force passing the
evaporation surface of the target becomes substantially vertical to
the evaporation surface.
[0027] Particularly, the arc evaporation source according to the
first invention of the present invention includes
[0028] a ring-shaped circumferential magnet and
[0029] a ring-shaped magnetic field generating mechanism, in
which
[0030] the direction of magnetization of the circumferential magnet
is along the radial direction,
[0031] the circumferential magnet is disposed surrounding the outer
circumference of the target such that the direction of
magnetization of the circumferential magnet is along the direction
parallel with the front surface of the target, and
[0032] the magnetic field generating mechanism is disposed ahead of
the target such that the axis of the magnetic field generating
mechanism is along a direction substantially vertical to the front
surface of the target, thereby generating a magnetic field
substantially vertical to the front surface of the target.
[0033] Alternatively, an arc evaporation source according to the
first invention of the present invention includes
[0034] a ring-shaped circumferential magnet and
[0035] a ring-shaped magnetic field generating mechanism in
which
[0036] the direction of magnetization of the circumferential magnet
is along the radial direction,
[0037] the circumferential magnet is disposed with the front end of
the circumferential magnet being situated at the back of the rear
surface of the target such that the direction of magnetization of
the circumferential magnet is along the direction parallel with the
front surface of the target, and
[0038] the magnetic field generating mechanism is disposed ahead of
the target such that the axis of the magnetic field generating
mechanism is along the direction substantially vertical to the
front surface of the target, thereby generating a magnetic field in
a direction substantially vertical to the front surface of the
target.
[0039] Further, an arc evaporation source according to a second
invention of the present invention includes
[0040] a ring-shaped circumferential magnet and
[0041] a rear surface magnet in which
[0042] the circumferential magnet is disposed surrounding the outer
circumference of the target such that the direction of
magnetization of the circumferential magnet is along a direction
parallel with the front surface of the target,
[0043] the rear surface magnet is disposed at the back of the
target such that the direction of magnetization of the rear surface
magnet is along a direction crossing the front surface of the
target, and
[0044] a magnetic pole in the radial inside of the circumferential
magnet and a magnetic pole of the rear surface magnet on the target
side have a polarity identical with each other.
[0045] Alternatively, an arc evaporation source according to the
second embodiment of the present invention includes
[0046] a ring-shaped circumferential magnet,
[0047] a rear surface magnet, and
[0048] a ring-shaped magnetic field generating mechanism in
which
[0049] the circumferential magnet is disposed at the back of the
rear surface of the target such that the direction of magnetization
of the circumferential magnet is along a direction parallel with
the front surface of the target,
[0050] the rear surface magnet is disposed such that the direction
of magnetization of the rear surface magnet crosses the front
surface of the target,
[0051] a magnetic pole in the radial inside of the circumferential
magnet and a magnetic pole of the rear surface magnet on the target
side have a polarity identical with each other and
[0052] the magnetic field generating mechanism is disposed ahead of
the target so as to generate a magnetic field in a direction
identical with that of the rear surface magnet and cause the lines
of magnetic force that have passed the front surface of the target
to pass the radial inside of the magnetic field generating
mechanism.
[0053] Further, an arc evaporation source according to a third
embodiment of the present invention includes
[0054] a ring-shaped circumferential magnet and
[0055] a ring-shaped rear surface magnet in which
[0056] the circumferential magnet is disposed surrounding the outer
circumference of the target and has a polarity where the direction
of magnetization is along a direction crossing the front surface of
the target and directed ahead or behind,
[0057] the rear surface magnet is disposed at the back of the
target, has an inner diameter larger than that of the target, and
has a polarity where the direction of magnetization is parallel
with the front surface of the target, and
[0058] the direction of magnetization of the rear surface magnet is
directed to the radial inside of the rear surface magnet when the
direction of magnetization of the circumferential magnet is
directed ahead and
[0059] the direction of magnetization of the rear surface magnet is
directed to a radial outside of the rear surface magnet when the
direction of magnetization of the circumferential magnet is
directed behind.
Advantageous Effects of Invention
[0060] Particularly, according to the first invention among the
inventions described above, the lines of magnetic force can be
controlled such that a magnetic force between the target and the
substrate is increased and the slope of the lines of magnetic force
at the target surface is vertical or in the direction from the
outer circumference to the center (inside) of the cathode
surface.
[0061] Particularly, according to the second invention among the
inventions described above, the lines of magnetic force can be
controlled such that slope of the lines of magnetic force at the
target surface is vertical or in the direction from the outer
circumference to the center (inside) of the cathode surface.
[0062] Particularly, according to the third invention among the
inventions described above, the lines of magnetic force of high
straightness extending in the direction from the target surface to
the substrate can be generated in a wide region at the target
surface in the arc evaporation source.
BRIEF DESCRIPTION OF DRAWINGS
[0063] FIG. 1(a) is a side elevational view illustrating a
schematic constitution of a film deposition apparatus having an arc
evaporation source according to a first embodiment of a first
invention of the present invention and (b) is a plan view
illustrating a schematic constitution of the film deposition
apparatus.
[0064] FIG. 2 is a view illustrating a schematic constitution of an
arc evaporation source according to the first embodiment the first
invention.
[0065] FIG. 3 are views illustrating a distribution of lines of
magnetic force of an arc evaporation source according to an
existent example.
[0066] FIG. 4 are views illustrating a distribution of lines of
magnetic force of an arc evaporation source according to an
exemplary invention of the first invention.
[0067] FIG. 5 is a view illustrating a schematic constitution of a
modified example of an arc evaporation source according to a
preferred embodiment of the first invention.
[0068] FIG. 6(a) is a side elevational view illustrating a
schematic constitution of a film deposition apparatus disposed with
an arc evaporation source according to a first embodiment of a
second invention of the present invention, and (b) is a plan view
illustrating a schematic constitution of the film deposition
apparatus.
[0069] FIG. 7 is a view illustrating a schematic constitution of an
arc evaporation source according to the first embodiment of the
second invention.
[0070] FIG. 8 is a view illustrating a schematic constitution of an
arc evaporation source according to a second embodiment of the
second invention.
[0071] FIG. 9 is a view illustrating a schematic constitution of an
arc evaporation source according to a third embodiment of the
second invention.
[0072] FIG. 10 are views illustrating a distribution of lines of
magnetic force of an arc evaporation source according to an
existent example.
[0073] FIG. 11 are views illustrating a distribution of lines of
magnetic force of an arc evaporation source according to a first
exemplary invention of a second invention.
[0074] FIG. 12 are views illustrating a distribution of lines of
magnetic force of an arc evaporation source according to a second
exemplary invention of the second invention.
[0075] FIG. 13 are views illustrating a distribution of lines of
magnetic force of an arc evaporation source according to a third
exemplary invention of the second invention.
[0076] FIG. 14 are views illustrating a distribution of lines of
magnetic force of an arc evaporation source according to a modified
example of the second exemplary invention of the second
invention.
[0077] FIG. 15 are views illustrating a distribution of lines of
magnetic force of an arc evaporation source according to another
modified example of the second exemplary invention of the second
invention.
[0078] FIG. 16 are views illustrating a distribution diagram of
lines of magnetic force of an arc evaporation source according to a
modified example of the third exemplary invention of the second
invention.
[0079] FIG. 17 are views illustrating a distribution of lines of
magnetic force of an arc evaporation source according to another
modified example of the third exemplary invention of the second
invention.
[0080] FIG. 18(a) is a side elevational view illustrating a
schematic constitution of a film deposition apparatus disposed with
an arc evaporation source according to a first embodiment of a
third invention of the present invention and (b) is a plan view
illustrating a schematic constitution of the film deposition
apparatus.
[0081] FIG. 19 is a view illustrating a schematic constitution of
an arc evaporation source according to a first embodiment of the
third invention.
[0082] FIG. 20 is a view illustrating a distribution of lines of
magnetic force of an arc evaporation source according to the first
embodiment of the third invention.
[0083] FIG. 21 is a view illustrating a distribution of lines of
magnetic force in an arc evaporation source according to a
comparative example.
[0084] FIG. 22 is a view illustrating a schematic constitution of
the arc evaporation source according to the second embodiment of
the third invention.
[0085] FIG. 23 is a view illustrating a distribution of lines of
magnetic force of an arc evaporation source according to the second
embodiment of the third invention.
[0086] FIG. 24 is a view illustrating a schematic constitution of
an arc evaporation source according to a third embodiment of the
third invention.
[0087] FIG. 25 is a view illustrating a distribution of lines of
magnetic force of an arc evaporation source according to the third
embodiment of the third invention.
DESCRIPTION OF EMBODIMENTS
First Invention
[0088] A first invention of the present invention is to be
described with reference to FIG. 1 to FIG. 5.
First Embodiment
First Invention
[0089] A first embodiment of a first invention is to be described
with reference to FIG. 1 and FIG. 2. FIG. 1 illustrate a film
deposition apparatus 6 provided with an arc evaporation source 1
(hereinafter referred to as a evaporation source 1) of the first
embodiment according to the first invention.
[0090] A film deposition apparatus 6 comprises a chamber 11, and a
rotary table 12 for supporting a substrate 7 as an object to be
processed, and an evaporation source 1 which is attached being
opposed to the substrate 7 are disposed in the chamber 1. The
chamber 11 has a gas introduction port 13 for introducing a
reaction gas into the chamber 11 and a gas exhaust port 14 for
exhausting a reaction gas from the inside of the chamber 11.
[0091] In addition, the film deposition apparatus 6 comprises an
arc power source 15 for applying a negative bias to a target 2 of
the evaporation source 1 (to be described later), and a bias power
source 16 for applying a negative bias to the substrate 7. Positive
electrodes of the arc source 15 and the bias power source 16 are
grounded to the ground 18.
[0092] As illustrated in FIG. 1, the evaporation source 1 comprises
a disk-shaped target 2 having a predetermined thickness which is
disposed with the evaporation surface being opposed to the
substrate 7 and a magnetic field forming unit 8 disposed near the
target 2. The term "disk-shaped" also means a circular cylindrical
shape having a predetermined height. The magnetic field forming
unit 8 can comprise a circumferential magnet 3. In this embodiment,
the chamber 11 acts as an anode. With such a constitution, the
evaporation source 1 serves as a cathode discharge arc evaporation
source.
[0093] The constitution of the evaporation source 1 provided to the
film deposition apparatus 6 is to be described below with reference
to FIG. 1 and FIG. 2. FIG. 2 is a view illustrating a schematic
constitution of the evaporation source 1 according to this
embodiment.
[0094] As described above, the evaporation source 1 comprises a
disk-shaped target 2 having a predetermined thickness and a
magnetic field forming unit 8 disposed near the target 2.
[0095] In the following description, the surface of the target 2,
as an evaporation surface, facing the substrate 7 (in the direction
to the substrate indicated by a blank arrow) is referred to as
"front surface" and the surface facing the opposite side (direction
opposite to the substrate) is referred to as "rear surface" (refer
to FIG. 1 and FIG. 2).
[0096] The target 2 comprises a material which is selected in
accordance with a thin film to be formed on the substrate 7. The
material includes ionizable materials such as metal materials, for
example, chromium (Cr), titanium (Ti), and titanium aluminum (TiAl)
and carbon (C).
[0097] The magnetic field forming unit 8 has a solenoid coil 9 as a
magnetic field generating mechanism and a ring-shaped (annular or
doughnut-shaped) circumferential magnet 3 disposed so as to
surround the outer circumference of the target 2. The
circumferential magnet 3 comprises a permanent magnet formed of a
neodymium magnet having high coercivity.
[0098] The solenoid coil 9 is a ring-shaped solenoid that generates
a magnetic field in the direction vertical to the front surface
(evaporation surface) of the target 2. The solenoid coil 9 has a
number of turns, for example, of about several hundred turns (for
example, 410 turns) and is wound around so as to form a coil of a
diameter somewhat larger than the diameter of the target 2. In this
embodiment, the solenoid coil 9 generates a magnetic field by a
current of about 2000 AT to 5000 AT.
[0099] As illustrated in FIG. 2, the solenoid coil 9 is disposed on
the front surface side of the target 2, and the projection shadow
of the solenoid coil 9 as viewed in the radial direction does not
overlap the projection shadow of the target 2. In this case, the
solenoid coil 9 is disposed so as to be coaxial with the target 2.
When the thus disposed target 2 and the solenoid coil 9 are
observed on the side of the substrate 7, a circular target 2 enters
substantially coaxially to the inside of a toroidal solenoid coil
9.
[0100] When a current is supplied to the thus disposed solenoid
coil 9, a magnetic field directing from the target 2 to the
substrate 7 is generated in the inside of the solenoid coil 9. The
lines of magnetic force passing the front surface of the target 2
can pass the inside of the solenoid coil 9.
[0101] The circumferential magnet 3 is a ring body and has a
predetermined thickness in the axial direction as described above.
The thickness of the circumferential magnet 3 is substantially
identical with or somewhat smaller than the thickness of the target
2.
[0102] The ring-shaped circumferential magnet 3 comprises, in
appearance, two surfaces of toroids (toroidal surfaces) parallel
with each other and two circumferential surfaces connecting the two
toroidal surfaces in the axial direction. The two circumferential
surfaces comprise an inner circumferential surface formed to the
inner circumference surface of the toroidal surface and an outer
circumferential surface formed to the outer circumference of the
toroidal surface. The width for the inner circumferential surface
and the outer circumferential surface is a thickness of the
circumferential magnet 3.
[0103] As illustrated in FIG. 2, the circumferential magnet 3 is
magnetized such that the inner circumferential surface forms a
N-pole and the outer circumferential surface forms a S-pole. The
drawing shows a solid arrow from the S-pole to the N-pole, and the
direction of the arrow is hereinafter referred to as a direction of
magnetization. The circumferential magnet 3 of this embodiment is
disposed such that the direction of magnetization is along the
direction parallel with the front surface of the target 2, that is,
the direction of magnetization is directed to the target 2.
[0104] The circumferential magnet 3 may have a ring-shaped or
annular shape integral configuration. Alternatively, the
circumferential magnet 3 may also comprise circular cylindrical or
cuboidal magnets arranged in a ring-shape or an annular shape so
that the direction of magnetization is horizontal to the surface of
the target 2.
[0105] The circumferential magnet 3 is disposed so as to surround
the outer circumference of the target 2 and disposed coaxially with
the target 2. The circumferential magnet 3 is disposed so as not to
exceed the range of the thickness of the target 2. Thus, projection
shadow of the circumferential magnet 3, as viewed in the radial
direction, overlaps the projection shadow of the target 2 as viewed
in the radial direction. That is, the circumferential magnet 3 is
disposed such that when the circumferential magnet 3 and the target
2 are projected in the direction parallel with the evaporation
surface of the target 2, respective shadows formed thereby overlap
to each other and the shadow of the circumferential magnet 3 is
completely contained within the shadow of the target 2.
[0106] As described above, the circumferential magnet 3 is disposed
to the evaporation source 1 such that the front end of the
circumferential magnet 3 as the toroidal surface on the front side
is situated at the back of (behind) the front surface of the target
2 and the rear end of the circumferential magnet 3 as the toroidal
surface on the rear side is situated in front (ahead) of the rear
surface of the target 2.
[0107] When the circumferential magnet 3 is disposed as described
above, lines of magnetic force near the target 2 can be converged
and made to pass the evaporation surface of the target 2 compared
with a case of using only the solenoid coil 9. Further, an
advantageous effect capable of making the direction of the lines of
magnetic force passing the evaporation surface of the target 2
substantially vertical to the evaporation surface is also
obtained.
[0108] The polarity of the solenoid coil 9 in the constitution
described above is such that the N-Pole is on the side of the
substrate 7 and the S-pole is on the side of the target 2. Further,
the polarity of the circumferential magnet 3 is such that the
N-Pole is on the side of the inner circumferential surface opposing
the target 2 and the S-pole is on the side of the outer
circumferential surface. However, identical distribution of lines
of magnetic force can be obtained also in the constitution with the
polarity opposed to that described above by reversing the direction
of the current supplied to the solenoid coil 9 and using a
circumferential magnet having the polarity of the inner
circumferential surface and the outer circumferential surface being
opposite to that of the circumferential magnet 3.
[0109] Then, a method of depositing a film in the film deposition
apparatus 6 using the evaporation source 1 is to be described.
[0110] At first, after evacuating the chamber 11 by vacuum drawing,
an inert gas such as an argon gas (Ar) is introduced from the gas
introduction port 13 and impurities such as oxide on the target 2
and the substrate 7 are removed by gas sputtering. After removing
the impurities, inside of the chamber 11 is again evacuated and a
reaction gas is introduced from the gas introduction port 13 into
the evacuated chamber 11.
[0111] When arc discharge is generated in this state on the target
2 installed in the chamber 11, materials constituting the target 2
are converted into plasmas and reacted with the reaction gas. Thus,
a nitride film, an oxide film, a carbide film, a carbonitride film,
an amorphous carbon film, etc. can be formed on the substrate 7
placed on the rotary table 12.
[0112] As the reaction gas, a nitrogen gas (N.sub.2) or an oxygen
gas (O.sub.2), or a hydrocarbon gas such as methane (CH.sub.4) may
be selected according to the application use, and the pressure of
the reaction gas in the chamber 11 may be controlled to about 1 to
7 Pa. Further, during film deposition, the target 2 is subjected to
discharge by flowing an arc current of 100 to 200 A, and applying a
negative voltage at 10 to 30 V from the arc power source 15.
Further, a negative voltage at 10 to 200 V may be applied to the
substrate 7 by the bias power source 16.
[0113] Further, it is preferred to constitute and arrange the
circumferential magnet 3 and the solenoid coil 9 such that the
magnetic field at the front surface of the target 2 is 100 gauss or
more. Thus, film deposition can be performed reliably. The magnetic
field on the front surface of the target 2 is more preferably 150
gauss.
[0114] The distribution state of the lines of magnetic force when
the film deposition is performed by using the evaporation source 1
of this embodiment is to be described specifically by the following
embodiments.
Embodiment
First Invention
[0115] With reference to FIG. 3 and FIG. 4, the feature of the
distribution of lines of magnetic force generated by the arc
evaporation source 1 according to the first embodiment of the first
invention is to be described.
[0116] Distribution diagrams of lines of magnetic force illustrated
in FIG. 3(a) and FIG. 4(a) show distribution of lines of magnetic
force from the side of the rear surface of the target 2 to the
surface of the substrate 7. In the distribution diagrams of lines
of magnetic force in FIG. 3(a) and FIG. 4(a), the right end shows
the position for the surface of substrate 7. The distribution
diagrams of lines of magnetic force illustrated in FIG. 3(b) and
FIG. 4(b) are enlarged views at the circumference of the target 2
in FIG. 3(a) and FIG. 4(a), respectively.
[0117] Various experimental conditions in the existent example and
examples of the invention to be described below are shown. The
target 2 is formed of titanium aluminum (TiAl) at an atomic ratio
of titanium (Ti) and aluminum (Al) of 1:1 and the size is (100 mm
diameter.times.16 mm thickness).
[0118] The circumferential magnet 3 is formed of a permanent magnet
and has a size of (170 mm outer diameter, 150 mm inner diameter,
and 10 mm thickness).
Existent Example
First Invention
[0119] For better understanding, distribution of lines of magnetic
force in an existent example, that is, in a case of using only the
solenoid coil 9 is to be described with reference to FIGS. 3(a) and
3(b).
[0120] Referring to FIG. 3(a), lines of magnetic force due to a
magnetic field formed by a solenoid coil 9 is introduced from the
side of the target 2 under convergence to the inside of the
solenoid coil 9 and then directed from the inside of the coil to
the surface of the substrate 7 under divergence.
[0121] Referring to FIG. 3(b), the lines of magnetic force passing
the front surface (evaporation surface) of the target 2 is inclined
in the direction from the outer circumference to the inner
circumference of the target 2, and converge from the rear surface
to the front surface of the target 2.
Exemplary Invention
First Invention
[0122] Distributions of lines of magnetic force when the arc
evaporation source 1 according to the first embodiment of the first
invention is used is to be described with reference to FIGS. 4(a)
and 4(b).
[0123] With reference to FIG. 4(a), for the lines of magnetic force
due to the magnetic field formed by the solenoid coil 9 and the
circumferential magnet 2, almost all of the lines of magnetic force
directing from the rear surface side of the target 2 to the
substrate 7 pass the front surface (evaporation surface) of the
target 2 and are introduced into the solenoid coil 9.
[0124] When compared with the existent example illustrated in FIG.
3(a), it can be seen that the density of the lines of magnetic
force between the target 2 and the solenoid coil 9 is increased.
That is, it can be said that the magnetic force between the target
2 and the solenoid coil 9 is increased by the use of the
circumferential magnet 2.
[0125] Referring to FIG. 4(b), it can be seen that the density of
lines of the magnetic force at the front surface (evaporation
surface) of the target 2 is increased more compared with the
existent example illustrated in FIG. 3(b). In addition, the lines
of magnetic force passing the evaporation surface of the target 2
is substantially vertical to the evaporation surface of the target
2 (in other words, substantially parallel with the normal line on
the target). However, it can be said that the lines of magnetic
force passing the evaporation surface of the target 2 are not only
substantially vertical to the evaporation surface but are inclined
somewhat in the direction from the outer circumference to the inner
circumference of the target 2.
[0126] Due to the inclination, a problem that arc spots move to the
outer circumference during discharge to make the discharge instable
or a problem that local discharge is caused only at the outer
circumference is less likely to occur.
[0127] As described above, the followings can be understood by the
first embodiment and the exemplary invention of the first
invention. That is, when the circumferential magnet 3 is disposed,
the magnetic force between the target 2 and the solenoid coil 9 can
be increased in order to efficiently draw out ionized materials of
the target from the evaporation surface of the target 2. When the
circumferential magnet 3 is disposed, the intensity of the magnetic
force between the target 2 and the solenoid coil 9 can be increased
without increasing the value of a current supplied to the solenoid
coil 9.
[0128] The position for disposing the circumferential magnet 3 is
not restricted to the position disclosed in the above-mentioned
embodiment.
[0129] For example, the circumferential magnet 3 may also be
disposed being displaced toward the rear surface side of the target
2. When the position of the circumferential magnet 3 is displaced
as described above, the front of the projection shadow as viewed
from the radial direction of the circumferential magnet 3 overlaps
the back of the projection shadow as viewed from the radial
direction of the target 2. That is, the circumferential magnet 3 is
disposed such that projection shadow formed when projecting the
circumferential magnet 3 and the target 2 in the direction parallel
with the evaporation surface of the target 2 are partially
overlapped to each other, and the side of the projection shadow of
the circumferential magnet 3 overlaps the back side of the
projection shadow of the target 2.
[0130] In this example, the central position in the direction of
the thickness of the circumferential magnet 3 where a solid arrow
is situated in FIG. 2, that is, an intermediate position between
the front end and the back end of the circumferential magnet is
within the range of the width along the direction of the thickness
of the target 2, and is disposed ahead (forward) of the rear
surface of the target 2.
[0131] As described above, the circumferential magnet 3 in this
example is disposed to the evaporation source 1 such that the front
end of the circumferential magnet 3 is disposed ahead of the rear
surface of the target 2. More specifically, it can be said that the
circumferential magnet 3 is disposed to the evaporation source 1
such that the front end as the toroidal surface at the front of the
target 2 is situated behind (backward) the front surface of the
target 2 and/or the rear end as the toroidal surface at the back of
the target 2 is disposed in ahead of the rear surface (forward) of
the target 2.
[0132] As described above, when the circumferential magnet 3 is
disposed being displaced to the rear surface side of the target 2,
it can be expected that the lines of the magnetic force passing the
evaporation surface of the target 2 is more vertical to the
evaporation surface of the target 2 (in other words, more parallel
with the normal line on the target). In addition, even when the
position of the evaporation surface changes due to consumption of
the target 2, uniformity of magnetic field at the evaporation
surface can be kept in a favorable state.
[0133] As described above, the circumferential magnet 3 is
preferably disposed such that the front end of the circumferential
magnet 3 is situated ahead of the rear surface of the target 2.
[0134] However, as illustrated in FIG. 5, the circumferential
magnet 3 can be sometimes disposed such that the circumferential
magnet 3 does not surround the outer circumference of the target 2,
that is, the front end of the circumferential magnet 3 is situated
at the back of the rear surface of the target 2 as a modified
example of the arc evaporation source 1 according to the first
embodiment of the first invention. In this example, the front of
the projection shadow of the circumferential magnet 3 as viewed in
the radial direction is situated behind the back of the projection
shadow of the target 2 as viewed in the radial direction. That is,
the circumferential magnet 3 can be disposed such that the
projection shadows formed when projecting the circumferential
magnet 3 and the target 2 in the direction parallel with the
evaporation surface of the target 2, do not overlap but the front
of the projection shadow of the circumferential magnet 3 is
situated at the back of the target 2.
[0135] Needles to say, if the circumferential magnet 3 is spaced
excessively behind the rear face of the target 2, the magnetic
force at the front surface of the target 2 is decreased and lines
of magnetic force that diverge to the outside of the target 2 are
formed. Then, for example, in a case where predetermined conditions
are satisfied, the circumferential magnet 3 may be disposed such
that the front end is situated behind the rear surface of the
target 2 and the direction of magnetization is along the direction
parallel with the front surface of the target 2 at a position where
the axis is situated behind the rear surface of the target 2 and
the direction of magnetization is along the direction parallel with
the front surface of the target 2 at a position where the axis
crosses the front surface of the target 2 substantially
vertically.
[0136] The conditions are, for example, such that the intensity of
lines of magnetic force at the front surface of the target 2 is
about 100 gauss or more, and lines of magnetic force inclined to
the central direction of the target is formed at the outer
circumference of the target 2. More preferably, the circumferential
magnet 3 is disposed so as to be substantially coaxial with the
target 2 (on coaxial axis).
Second Invention
[0137] A second invention of the present invention is to be
described with reference to FIGS. 6 to 17.
First Embodiment
Second Invention
[0138] With reference to FIG. 6 and FIG. 7, a first embodiment of
the second invention is to be described. FIG. 6 illustrate a film
deposition apparatus 106 provided with an arc evaporation source
101a according to the first embodiment of the second invention
(hereinafter referred to as an evaporation source 101a).
[0139] A film deposition apparatus 106 comprises a chamber 111, and
a rotary table 112 for supporting a substrate 107 as an object to
be processed and an evaporation source 101a which is attached being
opposed to the substrate 107 are disposed in the chamber 111. The
chamber 111 has a gas introduction port 113 for introducing a
reaction gas into the chamber 111 and a gas exhaust port 114 for
exhausting a reaction gas from the inside of the chamber 111.
[0140] In addition, the film deposition apparatus 106 comprises an
arc power source 115 for applying a negative bias to a target 102
of the evaporation source 101 (to be described later), and a bias
power source 116 for applying a negative bias to the substrate 107.
Positive electrodes of the arc source 115 and the bias power source
116 are grounded to a ground 118.
[0141] As illustrated in FIG. 6, the evaporation source 101a
comprises a disk-shaped target 102 having a predetermined thickness
and disposed with the evaporation surface being opposed to the
substrate 107 and a magnetic field forming unit 108 disposed near
the target 102. The term "disk-shaped" also means a circular
cylindrical shape having a predetermined height. The magnetic field
forming unit 108 comprises a circumferential magnet 103 and a rear
surface magnet 104. In this embodiment, the chamber 111 serves as
an anode. With such a constitution, the evaporation source 101a
serves as a cathode discharge arc evaporation source.
[0142] With reference to FIG. 6 and FIG. 7, the constitution of the
evaporation source 101a provided to the film deposition apparatus
106 is to be described below. FIG. 7 is a view illustrating a
schematic constitution of the evaporation source 101a according to
this embodiment.
[0143] As described above, the evaporation source 101a comprises a
disk-shaped target 102 having a predetermined thickness and a
magnetic field forming unit 108 disposed near the target 102.
[0144] In the following description, the surface of the target 102,
as an evaporation surface, facing the substrate 107 (in the
direction to the substrate indicated by a blank arrow) is referred
to as "front surface" and the surface thereof facing the opposite
side (counter-substrate direction) is referred to as "rear surface"
(refer to FIG. 6 and FIG. 7).
[0145] The target 102 comprises a material which is selected in
accordance with a thin film to be formed on the substrate 107. The
material includes ionizable materials such as metal materials, for
example, chromium (Cr), titanium (Ti), and titanium aluminum (TiAl)
and carbon (C).
[0146] The magnetic field forming unit 108 has a ring-shaped
(annular or doughnut-shaped) circumferential magnet 103 disposed so
as to surround the outer circumference of the target 102 and a rear
surface magnet 104 disposed at the back of the rear surface of the
target 102. The circumferential magnet 103 and the rear surface
magnet 104 comprise a permanent magnet formed of a neodymium magnet
having high coercivity.
[0147] The circumferential magnet 103 is a ring body and has a
predetermined thickness in the axial direction as described above.
The thickness of the circumferential magnet 103 is substantially
equal with or somewhat smaller than the thickness of the target
102.
[0148] The ring-shaped circumferential magnet 103 comprises, in
appearance, two surfaces of toroids parallel with each other
(toroidal surfaces) and two circumferential surfaces that connect
the two toroidal surfaces in the axial direction. The two
circumferential surfaces comprise an inner circumferential surface
formed to the inner circumference of the toroidal surface and an
outer circumferential surface formed to the outer circumference of
the toroidal surface. The width for the inner circumferential
surface and the outer circumferential surface is a thickness of the
circumferential magnet 103.
[0149] As illustrated in FIG. 7, the circumferential magnet 103 is
magnetized such that the inner circumferential surface forms a
N-pole and the outer circumferential surface forms a S-pole. The
drawing shows a solid (black) arrow from the S-pole to the N-pole
and the direction of the arrow is hereinafter referred to as
direction of magnetization. The circumferential magnet 103 of this
embodiment is disposed such that the direction of magnetization is
along the direction parallel with the front surface of the target
102, that is, such that the direction of magnetization is directed
to the target 102.
[0150] The circumferential magnet 103 may also has an integrated
ring-shaped or annular shaped configuration. Alternatively, the
circumferential magnet 103 may also comprise circular cylindrical
or cuboidal magnets arranged in a ring-shape or an annular shape so
that the direction of magnetization is horizontal to the surface of
the target 102.
[0151] The circumferential magnet 103 is disposed so as to surround
the outer circumference of the target 102 and is disposed coaxially
with the target 102. The circumferential magnet 103 is disposed so
as not to exceed the range of the thickness of the target 102.
Thus, a projection shadow of the circumferential magnet 103 as
viewed in the radial direction overlaps a projection shadow as
viewed in the radial direction of the target 102. That is, the
circumferential magnet 103 is disposed such that when the
circumferential magnet 103 and the target 102 are projected in the
direction parallel with the evaporation surface of the target 102,
respective projection shadows formed by projection overlap to each
other and the projection shadow of the circumferential magnet 103
is completely included within the shadow of the target 102.
[0152] Thus, the circumferential magnet 103 is disposed to the
evaporation source 101a such that the front end of the
circumferential magnet 103 which is the toroidal surface on front
of the circumferential magnet 103 is situated at the back (behind)
of the front surface of the target 102 and the rear end of the
circumferential magnet 103 which is the toroidal surface of the
front of the circumferential magnet 103 is situated ahead (forward)
of the rear surface of the target 102.
[0153] Further, the circumferential magnet 103 is disposed such
that an intermediate position between the front end and the rear
end is aligned with an intermediate position between the front
surface and the rear surface of the target 102.
[0154] The rear surface magnet 104 comprises a non-ring shaped
magnetic core 105 and two disk-shaped rear surface magnets 104A and
104B sandwiching the magnet core 105. The disk-shaped rear surface
magnets 104A and 104B are also non-ring shaped likewise the
magnetic core 105. The term "non-ring shaped" means not an annular
shape of a doughnut-like shape in which an aperture is formed in
the radial inside but means a solid shape such as a disk-like shape
or a circular cylinder shape. That is, "non-ring shape" means such
a shape that normal lines directing from the surface to the outward
do not intersect each other. In view of the knowledge so far, it
has been found that the thickness of the magnet at the rear surface
side should be increased in order to efficiently extend the lines
of magnetic force to the substrate. For this purpose, in this
embodiment, two magnets, that is, disk-shaped rear surface magnets
104A and 104B are disposed being spaced apart from each other for
increasing the thickness, and the space therebetween is filled with
the magnetic core 105 as a magnetic body to prevent lowering of the
magnetic force.
[0155] As illustrated in FIG. 7, the disk-shaped rear surface
magnets 104A and 104B are each magnetized such that one of disk
surfaces forms a N-pole and the other of the disk surfaces forms a
S-pole. The disk-shaped rear surface magnets 104A and 104B sandwich
the magnetic core 105 between the surface on the side of the S-pole
of the disk-shaped rear surface magnet 104A and the surface on the
side of the N-pole of the disk-shaped rear surface magnet 104B to
direct the magnetization direction to an identical direction.
[0156] The thus constituted rear surface magnet 104 is disposed to
the side of the rear surface of the target 102 such that the
direction of magnetization is along the axis of the target 102, and
the direction of magnetization is vertical to the evaporation
surface of the target 102. Further, the rear surface magnet 104 is
disposed such that the N-pole side of the disk-shaped rear surface
magnet 104A is directed to the target 102. The rear surface magnet
104 is disposed such that the axis thereof is substantially aligned
with the axis of the target 102.
[0157] The evaporation source 101a is constituted by disposing the
circumferential magnet 103 and the rear surface magnet 104 to the
target 102 as described above. In this embodiment, the direction of
magnetization in the circumferential magnet 103 is directed to the
direction parallel with the front surface of the target 102, that
is, directed to the target 102. Further, since the magnetic pole on
the inner circumference of the circumferential magnet 103 is a
N-pole and the magnetic pole of the of the rear surface magnet 104
facing the target 102 is also the N-pole, the magnetic pole in the
radial inside of the circumferential magnet 103 and the magnetic
pole of the rear surface magnet 104 facing the target 102 have an
identical polarity.
[0158] As described above, since the circumferential magnet 103 and
the rear surface magnet 104 face the target 102 at the identical
polarity, the magnetic field formed by the circumferential magnet
103 and the magnetic field formed by the rear surface magnet 104
can be combined. This can provide an effect capable of making the
direction of the lines of magnetic force that pass the evaporation
surface of the target 102 substantially vertical to the evaporation
surface, and introducing the lines of magnetic force in the
direction of the substrate 107.
[0159] As described above, since the circumferential magnet and the
rear surface magnet 104 may face the target 102 each at an
identical magnetic pole, the evaporation source 101a may also be
constituted such that the circumferential magnet 103 and the rear
surface magnet 104 face the target 102 each at the S-pole.
[0160] Then, a film deposition method in the film deposition
apparatus 106 using the evaporation source 101a is to be
described.
[0161] At first, after evacuating the chamber 111 by vacuum
drawing, an inert gas such as an argon gas (Ar) is introduced from
the gas introduction port 113 and impurities such as oxides on the
target 102 and the substrate 107 are removed by gas sputtering.
After removing the impurities, inside of the chamber 111 is again
evacuated and a reaction gas is introduced from the gas
introduction port 113 into the evacuated chamber 111.
[0162] When arc discharge is generated on the target 102 installed
in the chamber 111 in this state, materials constituting the target
102 are converted into plasmas and are reacted with the reaction
gas. Thus, a nitride film, an oxide film, a carbide film, a
carbonitride film, an amorphous carbon film, etc. can be formed
over the substrate 107 which is placed on the rotary table 112.
[0163] As the reaction gas, a nitrogen gas (N.sub.2) or an oxygen
gas (O.sub.2), or a hydrocarbon gas such as methane (CH.sub.4) may
be selected according to the application use and the pressure of
the reaction gas in the chamber 111 may be at about 1 to 7 Pa.
Further, during film deposition, the target 102 is subjected to
discharge by flowing an arc current of 100 to 200 A and applying a
negative voltage at 10 to 30 V from the arc power source 115.
Further, a negative voltage of 10 to 200 V may be applied to the
substrate 107 by the bias power source 116.
[0164] Further, it is preferred to constitute and arrange the
circumferential magnet 103 and the rear surface magnet 104 such
that the magnetic field on the front surface of the target 102 is
100 gauss or more.
[0165] Thus, films can be deposited reliably. The magnetic field on
the front surface of the target 102 is more preferably 150
gauss.
[0166] The distribution state of the lines of magnetic force when
film deposition is performed by using the evaporation source 101a
of this embodiment is to be described specifically by the following
examples.
Second Embodiment
Second Invention
[0167] Then, a second embodiment of the second invention is to be
described with reference to FIG. 8.
[0168] FIG. 8 is a view illustrating a schematic constitution of an
arc evaporation source 101b used in a film deposition apparatus 106
according to this embodiment.
[0169] An arc evaporation source 101b in this embodiment comprises
a disk-shaped target 102 having a predetermined thickness and a
magnetic field forming unit 108 disposed near the target 102 in the
same manner as the arc evaporation source 101a in the first
embodiment of the second invention. The magnetic field forming unit
108 has a ring-shaped (annular) circumferential magnet 103 disposed
so as to surround the outer circumference of the target 102, and a
rear surface magnet 104 disposed at the rear surface side of the
target 102.
[0170] As described above, the evaporation source 101b in this
embodiment has the same constitution as that in the arc evaporation
source 101a in the first embodiment of the first invention but it
is different only for the arrangement of the circumferential magnet
103.
[0171] Arrangement of the circumferential magnet 103 of the
evaporation source 101b in this embodiment is to be described
below.
[0172] Referring to FIG. 8, when taking notice on the position of
the circumferential magnet 103 relative to the target 102, it can
be seen that the circumferential magnet 103 is disposed to the
target 102 being displaced to the side of the rear surface magnet
104 (rear surface side). When the position of the circumferential
magnet 103 is displaced as described above, the front of a
projection shadow as viewed in the radial direction of the
circumferential magnet 103 overlaps the back of the projection
shadow of the target 102 as viewed in the radial direction. That
is, the circumferential magnet 103 is disposed such that when the
circumferential magnet 103 and the target 102 are projected in the
direction parallel with the evaporation surface of the target 102,
respective projection shadows formed by projection partially
overlap to each other and such that the front side of the
projection shadow of the circumferential magnet 103 overlaps the
back of the projection shadow of the target 102.
[0173] In this case, a central position in the direction of the
thickness of the circumferential magnet 103 shown by solid arrows
for the circumferential magnet 103 in FIG. 8, that is, an
intermediate position between the front end and the rear end of the
circumferential magnet 103 is disposed ahead (forward) of the rear
surface of the target 102 within a range of the width along the
direction of the thickness of the target 102.
[0174] That is, the circumferential magnet 103 in this embodiment
is disposed to the evaporation source 101b such that the front end
is disposed ahead of the rear surface of the target 102 and the
rear end is disposed behind the rear surface of the target 102.
Referring more specifically, the circumferential magnet 103 in this
embodiment is provided to the evaporation source 101b with the
intermediate position between the front end and the rear end being
behind (backward) an intermediate position between the front
surface and the rear surface of the target 102.
[0175] As described above, when the circumferential magnet 103 is
disposed to the target 102 being displaced to the rear surface
magnet 104, an effect capable of favorably keeping the uniformity
of the magnetic field at the evaporation surface can be obtained
even when the position of the evaporation source is changed due to
consumption of the target 102, in addition to the effect of the
first embodiment.
[0176] Since the second embodiment of the second invention is
substantially identical with the first embodiment except for the
disposition of the circumferential magnet 103 shown above,
explanation therefor is to be omitted.
[0177] The state of a distribution of lines of magnetic force when
a film is deposited by using the evaporation source 101b of the
second embodiment of the second invention is to be described
specifically with reference to examples to be described later.
Third Embodiment
Second Invention
[0178] A third embodiment of the second invention is to be
described referring to FIG. 9.
[0179] FIG. 9 is a view illustrating a schematic constitution of an
arc evaporation source 101c used in a film deposition apparatus 106
according to this embodiment.
[0180] The arc evaporation source 101c in this embodiment is
different from the arc evaporation source 101a in the first
embodiment of the second invention in that it has a solenoid coil
109 as a magnetic field generating mechanism.
[0181] Other constitutions, for example, a disk-shaped target 102
having a predetermined thickness, a ring-shaped circumferential
magnet 103 disposed so as to surround the outer circumference of
the target 102, a rear surface magnet 104 disposed at the back of
the target 102, etc. are substantially identical with those in the
first embodiment.
[0182] Therefore, constitution and arrangement of the solenoid coil
109 of the evaporation source 101c are to be described.
[0183] The solenoid coil 109 is a ring-shaped solenoid that
generates a magnetic field in the direction identical with that of
the rear surface magnet 104. The solenoid coil 109 has a number of
turns, for example, about several hundreds of turns (for example,
410 turns) and is wound around so as to form a coil of a diameter
somewhat larger than the diameter of the target 102. In this
embodiment, the solenoid coil 109 generates a magnetic field by a
current of about 2000 AT to 5000 AT.
[0184] As illustrated in FIG. 9, the solenoid coil 109 is disposed
in front of the target 102 and a projection shadow of the solenoid
coil 109 as viewed in the radial direction does not overlap the
projection shadow of the target 102. In this case, the solenoid
coil 109 is disposed so as to be coaxial with the target 102. When
the thus arranged target 102 and the solenoid coil 109 are viewed
from the rear surface magnet 104 and the substrate 107, the
circular target 102 enters substantially coaxially to the inside of
the annular solenoid coil 109.
[0185] A current is supplied to the thus disposed solenoid coil 109
to generate a magnetic field inside the solenoid coil 109 that
flows from the target 102 to the substrate 107. In this embodiment,
lines of magnetic force passing the front surface of the target 102
can pass the solenoid coil 109.
[0186] When the solenoid coil 109 is disposed as described above,
an effect capable of suppressing divergence of lines of magnetic
force that have passed the evaporation surface of the target 102
thereby maintaining a high density of lines of magnetic force as
far as the surface of the substrate 107 can also be obtained in
addition to the effect of the first embodiment. Further, when the
solenoid coil 109 is disposed between the target 102 and the
substrate 107, an effect capable of improving the ion transporting
efficiency from the target 102 to the substrate 107 can also be
expected.
[0187] The state of distribution of lines of magnetic force in a
case of depositing films by using the evaporation source 101c of
the third embodiment is to be described specifically by way of the
examples to be described below.
Example
[0188] Since the arc evaporation sources 101a to 101c of the first
embodiment to the third embodiment of the second invention are
different respectively for the arrangement of the circumferential
magnet 103, presence or absence of the solenoid coil 109, etc.,
distributions of generated lines of magnetic force are also
different respectively.
[0189] With reference to FIG. 10 to FIG. 13, distributions of the
lines of the magnetic force generated from the arc evaporation
sources 101a to 101c of the first embodiment to the third
embodiment are to be described as a first exemplary invention to a
third exemplary invention.
[0190] The distribution diagrams of lines of magnetic force
illustrated in FIG. 10(a), FIG. 11(a), FIG. 12(a), and FIG. 13(a)
illustrate distributions of lines of magnetic force from the rear
surface magnet 104 to the surface of the substrate 107. In each of
the distribution diagrams of the lines of magnetic force in FIG.
10(a) to FIG. 13(a), the right end illustrates a position for the
surface of the substrate 107. The distribution diagrams of the
lines of magnetic force illustrated in FIGS. 10(b), FIG. 11(b),
FIG. 12(b), and FIG. 13(b) are enlarged views at the circumference
of the target 102 in FIG. 10(a) to FIG. 13(a), respectively.
[0191] Various experimental conditions are shown for an existent
example and each of exemplary inventions to be described below. For
example, the size of the target 102 is (100 mm diameter.times.16 mm
thickness). The size for each of the disk-shaped rear surface
magnets 104A and 104B is (100 mm diameter.times.4 mm thickness).
The size of the magnetic core 105 is (100 mm diameter.times.30 mm
thickness). The size of the circumferential magnet 103 is (150 mm
inner diameter, 170 mm outer diameter, and 10 mm thickness). The
intensity of the magnetic field at the surface of the target 102 is
150 gauss or more.
Existent Example
Second Invention
[0192] For better understanding, with reference to FIGS. 10(a) and
10(b), a distribution diagram of lines of magnetic force is to be
described at first for an existent example, that is, in a case of
using only the rear surface magnetic 104.
[0193] With reference to FIG. 10(a), lines of magnetic force
emitting from the rear surface magnet 104 are directed to the
surface of the substrate 107 under divergence while being inclined
to the outer circumferential direction of the rear surface magnet
104.
[0194] With reference to FIG. 10(b), lines of magnetic force
passing the evaporation surface of the target 102 diverge from the
rear surface to the front surface of the target 102 while being
inclined in the outer circumferential direction of the target
102.
First Exemplary Invention
Second Invention
[0195] With reference to FIGS. 11(a) and 11(b), a distribution of
lines of magnetic force in a case of using the arc evaporation
source 101a according to the first embodiment of the second
invention is to be described.
[0196] With reference to FIG. 11(a), lines of magnetic force
emitting from the rear surface magnetic 104 are suppressed from
diverging at a position for the circumferential magnet 103 and the
density of the lines of magnetic force passing the target 102 is
higher than that of the existent example particularly near the
center of the target 102.
[0197] With reference to FIG. 11(b), the lines of magnetic force
passing the evaporation surface of the target 102 are substantially
vertical to the evaporation surface of the target 102 (that is,
substantially parallel with the normal line on the target).
Second Exemplary Invention
Second Invention
[0198] With reference to FIGS. 12(a) and 12(b), a distribution of
lines of magnetic force in a case of using the arc evaporation
source 101b according to the second embodiment of the second
invention is to be described.
[0199] With reference to FIG. 12(a), lines of magnetic force
emitting from the rear surface magnet 104 are suppressed from
diverging at a position for a circumferential magnet 103 and the
density of lines of magnetic force passing a target 102 is higher
than that of the existent example particularly near the center of
the target 102.
[0200] With reference to FIG. 12(b), the lines of magnetic force
passing the evaporation surface of the target 102 are substantially
vertical to the evaporation surface of the target 102 (that is,
substantially parallel with the normal line on the target).
Further, when the exemplary invention is compared with the existent
example, from the center to the rear surface side in the direction
of the thickness of the target 102, it can be seen that the lines
of magnetic force at the outer circumference of the exemplary
invention are more parallel relative to the normal line on the
target. Accordingly, it can be said that the density of the lines
of the magnetic force in the target 102 is more uniform than that
of the existent example.
[0201] FIGS. 14(a) and 14(b) illustrate a distribution of lines of
magnetic force in an modified example to the exemplary invention.
The arc evaporation source illustrated in FIGS. 14(a) and 14(b) has
a target 102, a circumferential magnet 103, and a rear surface
magnet 104 in the same manner as in the arc evaporation source 101b
in FIGS. 12(a) and 12(b) according to the second embodiment of the
second invention. In the arc evaporation source of FIGS. 14(a) and
14(b), the circumferential magnet 103 is disposed behind the rear
surface of the target 102 different from the arc evaporation source
101b in FIGS. 12(a) and 12(b). In this case, the front end of the
circumferential magnet 103 is situated behind the rear surface of
the target 102 by about 5 mm to 10 mm.
[0202] In the distribution diagrams of lines of magnetic force in
FIGS. 14(a) and 14(b), it can be seen that the lines of magnetic
force at the front surface (evaporation surface) of the target 102
diverge while being inclined more to the radial outer side of the
target 102 relative to the evaporation surface than that in FIGS.
12(a) and 12(b). This is not preferred, since the arc discharge is
localized to the outer circumference of the target 102. That is, in
the arc evaporation source having the target 102, the
circumferential magnet 103, and the rear surface magnet 104, it is
not preferred that the circumferential magnet 103 is disposed
behind the rear surface of the target 102.
[0203] FIGS. 15(a) and 15(b) illustrate a distribution of lines of
magnetic force in another modified example to the exemplary
invention. The arc evaporation source illustrated in FIGS. 15(a)
and 15(b) has a target 102, and an circumferential magnet 103 in
the same manner as the arc evaporation source 101b in FIGS. 12(a)
and 12(b) according to the second embodiment of the second
invention. However, a solenoid coil 110 which is a ring-shaped
solenoid having the same constitution as that of the solenoid coil
109 is used instead of the surface magnet 104 comprising the
permanent magnet. The position of the circumferential magnet 103 to
the target 102 in the arc evaporation source of FIGS. 15(a) and
15(b) is substantially identical with the position for the
circumferential magnet 103 of the arc evaporation source 101b in
FIGS. 12(a) and 12(b). The solenoid coil 110 is disposed
substantially coaxially with the target 102 at a position
substantially identical with that of the rear surface magnet 104 in
FIGS. 12(a) and 12(b). The solenoid coil 110 has about 100 mm inner
diameter, 200 mm outer diameter, and about 50 mm thickness. The
solenoid coil 110 is disposed behind the target 102 by about 64 mm.
The magnetic force of the solenoid coil 110 is adjusted such that
the magnetic flux density at the front surface of the target 102 is
substantially identical with the case of using the rear surface
magnet 104.
[0204] In the distribution diagram of lines of magnetic force in
FIGS. 15(a) and 15(b), it can be seen that a magnetic field
substantially equivalent with that of the distribution diagram of
lines of magnetic force in FIGS. 12(a) and 12(b) is formed. That
is, it can be said that a substantially equivalent magnetic field
can be formed also in a case of using the solenoid coil 110 instead
of the rear surface magnet 104 comprising the permanent magnet.
Third Exemplary Invention
Second Invention
[0205] With reference to FIGS. 13(a) and 13(b), a distribution of
lines of magnetic force in a case of using the arc evaporation
source 101c according to a third embodiment of the second invention
is to be described.
[0206] With reference to FIG. 13(a), lines of magnetic force
emitting from the rear surface magnet 104 is restricted from
diverging at a position of the circumferential magnet 103, and the
density of the lines of magnetic force passing the target 102 is
higher than that of the existent example particularly near the
center of the target 102. Lines of magnetic force that have passed
the evaporation surface of the target 102 and are being diverged
are suppressed from diverging at the position of the solenoid coil
109 and again become substantially parallel with the normal line on
the target.
[0207] With reference to FIG. 13(b), lines of magnetic force
passing the evaporation surface of the target 102 are substantially
vertical to the evaporation surface of the target 102, or inclined
centrally to the target 102. Thus, it can be said that the lines of
magnetic force in the third exemplary invention become most
parallel to the normal line on the target in the direction of the
thickness of the target 102 from the center to the rear surface,
compared with the existent example and the first and second
exemplary inventions.
[0208] FIGS. 16(a) and 16(b) illustrate a distribution of lines of
magnetic force in a modified example of the exemplary invention.
The arc evaporation source illustrated in FIGS. 16(a) and 16(b) has
a target 102, a circumferential magnet 103, a rear surface magnet
104, and a solenoid coil 109 in the same manner as the arc
evaporation source 101c of FIGS. 13(a) and 13(b) according to the
third embodiment of the second invention. In the arc evaporation
source of FIGS. 16(a) and 16(b), the circumferential magnet 103 is
disposed behind the rear surface of the target 102 different from
the arc evaporation source 101c of FIGS. 13(a) and 13(b). In the
example, the front end of the circumferential magnet 103 is
situated behind the rear surface of the target 102 by about 5 mm to
10 mm.
[0209] For the distribution diagram of the lines of magnetic force
in FIGS. 16(a) and 16(b), it can be seen that a magnetic field
substantially equivalent with the distribution diagram of the lines
of magnetic force in FIGS. 13(a) and 13(b) is formed. In this
modified example, it can be seen that a magnetic field
substantially equivalent with that of the distribution diagram of
the lines of magnetic force in FIGS. 13(a) and 13(b) can be formed
even when the circumferential magnet 103 is disposed at the back of
the rear surface of the target 102 by about 5 mm to 10 mm. That is,
in the constitution of this modified example, it can be seen that
an allowable range in accordance with the size of each of the
constituent members and the density of the generated lines of
magnetic force is present for the distance between the front end of
the circumferential magnet 103 and the rear surface of the target
102 in order to form a magnetic field substantially equivalent with
that of the distribution diagram of lines of magnetic force in
FIGS. 13(a) and 13(b). The allowable range is about twice the
thickness of the target 102.
[0210] FIGS. 17(a) and 17(b) illustrate a distribution of lines of
magnetic force in another modified example of the exemplary
invention. The arc evaporation source illustrated in FIGS. 17(a)
and 17(b) has a target 102, a circumferential magnet 103, and a
solenoid coil 109 in the same manner as the arc evaporation source
101c in FIGS. 13(a) and 13(b) according to the third embodiment of
the second invention. However, a solenoid coil 110 is used instead
of the rear surface magnet 102 comprising the permanent magnet. In
the arc evaporation source of FIGS. 12(a) and 12(b), the position
of the circumferential magnet 103 to the target 102 is
substantially equal with the position in the arc evaporation source
101c in FIGS. 13(a) and 13(b). The solenoid coil 110 has the
substantially identical constitution with that of the solenoid coil
110 in FIGS. 15(a) and 15(b) and is disposed substantially
coaxially with the target 102 at a position substantially identical
with that of the rear surface magnet 104 in FIGS. 13(a) and 13(b).
In FIGS. 17(a) and 17(b), the solenoid coil 110 is disposed behind
the target 102 by about 64 mm.
[0211] In the distribution diagram of lines of magnetic force in
FIGS. 17(a) and 17(b), it can be seen that a magnetic field
substantially equivalent with the distribution diagram of lines of
magnetic force in FIGS. 13(a) and 13(b) is formed. That is, it can
be said that a substantially equivalent magnetic field can be
formed also in a case of using the solenoid coil 110 instead of the
rear surface magnet 104 comprising the permanent magnet.
Third Invention
[0212] A third invention of the present invention is to be
described with reference to FIGS. 18 to 25.
First Embodiment
Third Invention
[0213] A first embodiment of a third invention is to be described
with reference to FIG. 18 to FIG. 21. FIG. 18 illustrate a film
deposition apparatus 206 provided with an arc evaporation source
201a according to the first embodiment of the third invention
(hereinafter referred to as an evaporation source 201a).
[0214] A film deposition apparatus 206 comprises a chamber 211, and
a rotary table 212 for supporting a substrate 207 as an object to
be processed, and an evaporation source 201a which is attached
being opposed to the substrate 207 are disposed in the chamber 201.
The chamber 211 has a gas introduction port 213 for introducing a
reaction gas into the chamber 211 and a gas exhaust port 214 for
exhausting a reaction gas from the inside of the chamber 211.
[0215] In addition, the film deposition apparatus 206 comprises an
arc power source 215 for applying a negative bias to a target 202
of the evaporation source 201a (to be described later), and a bias
power source 216 for applying a negative bias to the substrate 207.
Positive electrodes of the arc source 215 and the bias power source
216 are grounded to a ground 218.
[0216] As illustrated in FIG. 18, the evaporation source 201a
comprises a disk-shaped target 202 having a predetermined thickness
which is disposed with the evaporation surface being faced to the
substrate 207 and a magnetic field forming unit 208a disposed near
the target 202. The term "disk-shaped" also means a circular
cylindrical shape of a predetermined height. The magnetic field
forming unit 208a comprises a circumferential magnet 203 and a rear
surface magnet 204a. In this embodiment, the chamber 211 acts as an
anode. With such a constitution, the evaporation source 201a serves
as a cathode discharge arc evaporation source.
[0217] With reference to FIG. 18 and FIG. 19, the constitution of
the evaporation source 201a provided to the film deposition
apparatus 206 is to be described below. FIG. 19 is a view
illustrating a schematic constitution of the evaporation source
201a according to this embodiment.
[0218] As described above, the evaporation source 201a comprises
the disk-shaped target 202 having a predetermined thickness and the
magnetic field forming unit 208a disposed near the target 202.
[0219] In the following description, the surface of the target 202,
as an evaporation surface, facing the substrate 207 (in the
direction to the substrate indicated by a blank arrow) is referred
to as "front surface (target front surface)" and the surface facing
the opposite side is referred to as "rear surface" (target rear
surface) (refer to FIG. 18 and FIG. 19).
[0220] The target 202 comprises a material which is selected in
accordance with a thin film to be formed on the substrate 207. The
material includes ionizable materials such as metal materials, for
example, chromium (Cr), titanium (Ti), and titanium aluminum
(TiAl), and carbon (C).
[0221] The magnetic field forming unit 208a has a ring-shaped
(annular or doughnut-shaped) circumferential magnet 203 disposed so
as to surround the outer circumference of the target 202 and a
ring-shaped (annular or doughnut-shaped) rear surface magnet 204a
disposed coaxially with the circumferential magnet 203 on the side
of the rear surface of the target 202. The circumferential magnet
203 and the rear surface magnet 204a each comprise a permanent
magnet formed of a neodymium magnet having high coercivity.
[0222] That is, the evaporation source 201a is constituted by
arranging the target 202, the circumferential magnet 203, and a
rear surface magnet 204a by substantially aligning the axes thereof
to each other.
[0223] The circumferential magnet 203 is a ring body as described
above and has an inner diameter which is somewhat larger (by about
1 to 2 times) than the diameter of the target 202, and has a
predetermined thickness along the axial direction. The thickness of
the circumferential magnet 203 is substantially equal with or
somewhat smaller than the thickness along the axial direction of
the target 202.
[0224] The ring-shaped circumferential magnet 203 comprises, in
appearance, two surfaces of toroids (toroidal surfaces) parallel
with each other and two circumferential surfaces connecting the two
toroidal surfaces in the axial direction. The two circumferential
surfaces comprise an inner circumferential surface formed to the
inner circumference of the toroidal surface and an outer
circumferential surface formed to the outer circumference of the
toroidal surface. The width for the inner circumferential surface
and the outer circumferential surface is a thickness of the
circumferential magnet 203 (thickness in the axial direction).
[0225] The shape of the inner circumferential surface of the
circumferential magnet 203 is formed such that when the
circumferential magnet 203 and the target 202 are projected along
the direction crossing the front surface of the target 202, the
shape of the projection shadow of the inner circumferential surface
of the circumferential magnet 203 and the shape of the projection
shadow of the target 202 are similar to each other.
[0226] As shown in FIG. 19, the circumferential magnet 203 has a
N-pole at the front toroidal surface (front end surface) facing the
substrate 207 and a S-pole at the rear toroidal surface (rear end
face) facing the opposite side. The drawing shows arrows directing
from the rear toroidal surface (S-pole) to the front toroidal
surface (N-pole) of the circumferential magnet 203 and the
direction of the arrow is hereinafter referred to as the direction
of magnetization. The circumferential magnet 203 of this embodiment
is disposed such that the direction of magnetization is along the
direction crossing the front surface of the target 202 and is
directed forward.
[0227] As described above, the circumferential magnet 203
preferably has an integrated ring-like or annular shape. However,
the circumferential magnet 203 may also comprise a plurality of
circular cylindrical or cuboidal magnets arranged in a ring-like or
annular shape such that the direction of magnetization is along the
direction crossing the front surface of the target 202 and is
directed forward.
[0228] The circumferential magnet 203 is disposed coaxially with
the target 202 so as to surround the outer circumference of the
target 202. In this case, the front toroidal surface of the
circumferential magnet 203 is on a plane identical with the front
surface of the target 202 and they are flush with each other, or is
disposed ahead of the front surface of the target 202.
[0229] For example, in FIG. 19, the target 202 is disposed such
that the front surface thereof does not exceed the range of the
thickness of the circumferential magnet 203. Accordingly, in this
embodiment, they are arranged such that a projection shadow of the
circumferential magnet 203 as viewed in the radial direction
overlaps a projection shadow of the target 202 as viewed in the
radial direction. That is, the circumferential magnet 203 is
disposed such that the projection shadows, which are formed when
the circumferential magnet 203 and the target 202 are projected in
a direction parallel with the front surface (evaporation surface)
of the target 202, overlap to each other and the projection shadow
of the circumferential magnet 203 is completely included in the
projection shadow of the target 202.
[0230] As described above, the circumferential magnet 3 is disposed
to the evaporation source 201a such that the front end face is on a
plane identical with the front surface of the target 202 or
situated ahead of the front surface of the target 202.
[0231] The rear surface magnet 204a is a ring body having a
diameter substantially identical with that of the circumferential
magnet 203 and has an inner diameter and an outer diameter
substantially equal with those of the circumferential magnet 203.
Accordingly, the rear surface magnet 204a has an inner diameter
somewhat larger than the diameter of the target 202 (about 1 to 2
times) and a predetermined thickness along the axial direction. The
thickness of the circumferential magnet 203 is somewhat larger than
the thickness of the target 202 and about twice the thickness of
the circumferential magnet 203.
[0232] The ring-shaped rear surface magnet 204a also comprises, in
appearance, two toroidal surfaces (front end face and rear end
face) parallel with each other and two circumferential surface
connecting the two toroidal surfaces in the axial direction (inner
circumferential surface and outer circumferential surface) in the
same manner as the circumferential magnet 203. The width of the
inner circumferential surface and that of the outer circumferential
surface is a thickness of the circumferential magnet 203 along the
axial direction.
[0233] As shown in FIG. 19, the rear surface magnet 204a is formed
such that the inner circumferential surface forms a N-pole and the
outer circumferential surface forms a S-pole. The drawing shows
solid arrows indicating the direction of magnetization from the
outer circumferential surface (S-pole) to the inner circumferential
surface (N-pole) of the rear surface magnet 204a. The rear surface
magnet 204a of this embodiment is disposed such that the direction
of magnetization is parallel with the front surface of the target
202 and is directed to the radial inside.
[0234] In the circumferential magnet 203 and the rear surface
magnet 204a of such a constitution, the front end surface of the
circumferential magnet 203 and the inner circumferential surface of
the rear surface magnet 204a have an identical polarity and, in
this state, the respective directions of magnetization are vertical
to each other.
[0235] As described above, since the direction of magnetization of
the circumferential magnet 203 and that of the rear surface magnet
204 are vertical to each other, the magnetic field formed by the
circumferential magnet 203 and the magnetic field formed by the
rear surface magnet 204a can be combined. Thus, the direction of
lines of the magnetic force passing the evaporation surface of the
target 202 can be made substantially vertical to the evaporation
surface. Further, this also provides an effect capable of
generating lines of magnetic force of high straightness that extend
from the surface of the target 202 to the substrate 207 in a wide
region on the surface of the target 202.
[0236] As has been described above, it may suffice that the front
end face of the circumferential magnet 203 and the inner
circumferential surface of the rear surface magnet 204a have an
identical polarity, and that the magnetization direction of the
circumferential magnet 203 and the magnetization of the rear
surface magnet 204a are in the directions vertical to each other.
Accordingly, the polarity of the circumferential magnet 203 and the
polarity of the rear surface magnet 204a may be reversed to those
of the configuration described above shown in FIG. 2, in which the
direction of magnetization of the circumferential magnet 203 and
the direction of magnetization of the rear surface electrode 204a
may be reversed respectively.
[0237] Then, a film deposition method in the film deposition
apparatus 206 using the evaporation source 201a is to be
described.
[0238] At first, after evacuating the chamber 211 by vacuum
drawing, an inert gas such as an argon gas (Ar) is introduced from
the gas introduction port 213 and impurities such as oxides on the
target 202 and the substrate 207 are removed by gas sputtering.
After removing the impurities, inside of the chamber 211 is again
evacuated and a reaction gas is introduced from the gas
introduction port 213 into the evacuated chamber 211.
[0239] When arc discharge is generated in this state on the target
202 installed in the chamber 211, materials constituting the target
202 are converted into plasmas and reacted with the reaction gas.
Thus, a nitride film, an oxide film, a carbide film, a carbonitride
film, an amorphous carbon film, etc. can be formed on the substrate
207 placed on the rotary table 212.
[0240] As the reaction gas, a nitrogen gas (N.sub.2) or an oxygen
gas (O.sub.2), or a hydrocarbon gas such as methane (CH.sub.4) may
be selected according to the application use and the pressure of
the reaction gas in the chamber 211 may be at about 1 to 10 Pa.
Further, during film deposition, the target 202 is subjected to
discharge by flowing an arc current of 100 to 200 A and applying a
negative voltage of 10 to 30 V from the arc power source 215.
Further, a negative voltage of 10 to 200 V may be applied to the
substrate 207 by the bias power source 216.
[0241] Further, it is preferred to constitute and arrange the
circumferential magnet 203 and the rear surface magnet 204 such
that the magnetic field on the front surface of the target 202 is
100 gauss or more. Thus, a film can be deposited reliably. The
magnetic field on the front surface of the target 202 is more
preferably 150 gauss.
First Exemplary Invention
Third Invention
[0242] With reference to FIG. 20, a distribution of lines of
magnetic force generated in the evaporation source 201a according
to the first embodiment is to be described. A distribution diagram
of lines of magnetic force illustrated in FIG. 20 shows a
distribution of lines of magnetic force from the back of the rear
surface magnet 204a to the surface of the substrate 207. In the
distribution diagram of the lines of magnetic force of FIG. 20, the
right end shows a position for the surface of the substrate
207.
[0243] Various experimental conditions are shown below. For
example, the size of the target 202 is (100 mm diameter.times.16 mm
thickness). The size of the circumferential magnet 203 is (150 mm
inner diameter, 170 mm outer diameter, and 10 mm thickness), and
the distance from the surface of the target 202 to the
circumferential magnet 203 is 5 mm. The size of the rear surface
magnet 204a is (150 mm inner diameter, 170 mm outer diameter, and
20 mm thickness), and the distance from the surface of the target
202 to the rear surface magnet 204a is 40 mm. The intensity of the
magnetic field at the surface of the target 202 is 150 gauss or
more.
[0244] With reference to FIG. 20, lines of magnetic force emitting
radially inside from the rear surface magnet 204a extend
substantially vertical to the target 202 while changing the
progressing direction so as to be along the axial direction of the
rear surface magnet 204a. Such lines of magnetic force are combined
with the lines of magnetic force emitting from the circumferential
magnet 203 and pass the evaporation surface of the target 202. From
the evaporation surface of the target 202, lines of magnetic force
of high straightness that extend in the direction to the substrate
are generated in a wide region at the evaporation surface of the
target 202. In other words, a great amount of vertical lines of
magnetic force (vertical components) are generated in the wide
region at the evaporation surface of the target 202.
[0245] In the drawing, attention is paid to lines of magnetic
forces at portions surrounded by two circles P at the outer
circumference of the target 202 in FIG. 20. Lines of magnetic force
after emitting from the evaporation surface at the target 202 are
curved at two circles P to the radial outside of the target 202,
that is, to the circumferential magnet 203. This indicates that the
components of the lines of the magnetic force vertical to the
evaporation surface of the target 202 are not substantially present
at the outer circumference of the target 202 surrounded by the two
circles P.
[0246] Electron emission points (arc spots) on the cathode side
generated in the film deposition apparatus 206 tend to be trapped
to a place where the components of the magnetic force substantially
parallel with the evaporation surface of the target 202 are
present, that is, to a place where the components of lines of
magnetic force vertical to the evaporation surface of the target
202 are not present. That is, the first exemplary invention can
avoid a disadvantage that the arc spots moving at a high speed on
the evaporation surface of the target 202 move to the outside of
the evaporation surface of the target 202 beyond the outer
circumference of the target 202. Thus, the arc spots can be
retained on the evaporation surface of the target 202.
Comparative Example
Third Invention
[0247] For clarifying the feature and the effect of the evaporation
source 201a according to this embodiment, description is to be made
on a comparative example relative to the first exemplary invention
described above.
[0248] FIG. 21 illustrates a distribution of lines of magnetic
force generated in the evaporation source according to this
comparative example. The evaporation source according to the
comparative example comprises a target and an circumferential
magnet identical with those of the evaporation source 201a
according to the first embodiment, and also has a rear surface
electromagnet 220 comprising a solenoid coil instead of the rear
surface magnet 204a of the evaporation source 201a. The evaporation
source according to this comparative example has a constitution
similar with that of the arc evaporation device disclosed in the
cited Patent reference 4.
[0249] Also the distribution diagram of lines of magnetic force
shown in FIG. 21 shows a distribution of lines of magnetic force
from the back of the rear surface electromagnet 220 to the surface
of the substrate. In the distribution diagram of lines of magnetic
force illustrated in FIG. 21, the right end shows a position for
the surface of the substrate.
[0250] Various experimental conditions are shown below. For
example, the size of the target is (100 mm diameter.times.16 mm
thickness). The size of the circumferential magnet is (150 mm inner
diameter, 170 mm outer diameter, and 10 mm thickness), and the
distance from the surface of the target 202 to the circumferential
magnet 203 is 5 mm. The size of the rear surface electromagnet 20
is (50 mm inner diameter, 100 mm outer diameter, and 25 mm
thickness) and the distance from the surface of the target 202 to
the rear surface electromagnet 20 is 45 mm. The magnetic field
intensity at the surface of the target 202 is 150 gauss or
more.
[0251] With reference to FIG. 21, lines of magnetic force emitting
from the outer circumference relative to the central region within
the diameter of the solenoid coil diverge outwardly relative to the
axis of the solenoid coil just after leaving the solenoid coil. The
diverged lines of magnetic force further diverge in the target and
are directed sideway of the target without reaching the front
surface of the target.
[0252] On the other hand, lines of magnetic force at high
straightness emit from the central region of the rear surface
electromagnet 220 and the lines of magnetic force transmit the
front surface of the target. However, the density of straight
forwarding lines of magnetic force is extremely lower than that of
the first exemplary invention shown in FIG. 20.
[0253] Further, a distribution of lines of magnetic force
corresponding to the portion of circles P illustrated in FIG. 20
for explaining the first exemplary invention is not present to the
outer circumference of the target in this comparative example. That
is, it can be said that retainment of the arc spots on the
evaporation surface of the target is difficult in this comparative
example.
Second Embodiment
Third Invention
[0254] A second embodiment of the third invention is to be
described with reference to FIG. 22 and FIG. 23.
[0255] FIG. 22 is a view illustrating a schematic constitution of
an arc evaporation source 201b according to a second embodiment of
the third invention (hereinafter referred to as an evaporation
source 201b). A film deposition apparatus 206 according to this
embodiment has an evaporation source 201b to be described later
instead of the evaporation source 201a according to the first
embodiment of the second invention. In the film deposition
apparatus 206 according to this embodiment, constitutions other
than the evaporation source 201b are identical with those described
in the first embodiment of the third invention, and identical
constituent elements carry same reference numerals, for which
descriptions are to be omitted.
[0256] The evaporation source 201b in this embodiment comprises a
disk-shaped target 202 having a predetermined thickness and a
magnetic field forming unit 208b disposed near the target 202 in
the same manner as the evaporation source 201a in the first
embodiment of the third invention. The magnetic field forming unit
208b has a circumferential magnet 203 and a rear surface magnet
204a alike the first embodiment and, further, has a rear surface
magnet 204a and has a rear surface magnet 204b (second rear surface
magnet) having the same constitution as that of the rear surface
magnet 204a, which is a ring body having a diameter substantially
identical with that of the circumferential magnet 203.
[0257] The ring-shaped rear surface magnet 204b is disposed at the
back of the rear surface magnet 204a and coaxially with the rear
surface magnet 204a and the circumferential magnet 203. Thus, the
direction of magnetization of the rear surface magnet 204b is
parallel and identical with the direction of the magnetization of
the rear surface magnet 204a. While the rear surface magnet 204a
and the rear surface magnet 204b are adjacent to each other, the
distance between them is not always arbitrary. It is preferred that
the rear surface magnet 204a and the rear surface magnet 204b are
disposed being close to each other so that repulsion exerts between
the rear surface magnet 204a and the rear surface magnet 204b to
each other.
[0258] As illustrated in FIG. 22, when the rear surface magnet 204a
and the rear surface magnet 204b are disposed coaxially being close
to each other, lines of magnetic force emitting from the rear
surface magnet 204a and diverging to the rear surface magnet 204b
and lines of magnetic force emitting from the rear surface magnet
204b and diverging to the rear surface magnet 204a repel to each
other. By the repulsion, divergence of lines of magnetic force
between the rear surface magnet 204a and the rear surface magnet
204b is suppressed, and a great amount of lines of magnetic force
at high straightness can be generated within the diameter of the
rear surface magnet 204a and the rear surface magnet 204b.
Second Exemplary Invention
Third Invention
[0259] With reference to FIG. 23, a distribution of lines of
magnetic force generated in the evaporation source 201b according
to the second embodiment of the third invention is to be described.
A distribution diagram of lines of magnetic force illustrated in
FIG. 23 shows a distribution of lines of magnetic force from the
back of the rear surface magnet 204b to the surface of the
substrate 207. In the distribution diagram of lines of magnetic
force in FIG. 23, the right end indicates a position for the
surface of the substrate 207.
[0260] Various experimental conditions are shown below. For
example, the size of a target 202 is (100 mm diameter.times.16 mm
thickness). The size of a circumferential magnet 203 is (150 mm
inner diameter, 170 mm outer diameter, and 10 mm thickness), and
the distance from the surface of the target 202 to the
circumferential magnet 203 is 5 mm.
[0261] The size of the rear surface magnet 204a is (150 mm inner
diameter, 170 mm outer diameter, and 20 mm thickness) and the
distance from the surface of the target 202 to the rear surface
magnet 204a is 60 mm. The size of the rear surface magnet 204b is
(150 mm inner diameter, 170 mm outer diameter, and 20 mm thickness)
and the distance from the surface of the target 202 to the rear
surface magnet 204b is 90 mm. The distance between the rear surface
magnet 204a and the rear surface magnet 204b is 10 mm.
[0262] The magnetic field intensity at the surface of the target
202 is 150 gauss or more.
[0263] Referring to FIG. 23, a great amount of lines of magnetic
force of high straightness emit from the rear surface magnet 204a
and the rear surface magnet 204b in a radially inward direction.
Lines of magnetic force extend substantially vertically to the
target 202 while changing the progressing direction so as to be
along the axial direction of the rear surface magnet 204a and the
rear surface magnet 204b. The lines of magnetic force are combined
with the lines of magnetic force emitting from the circumferential
magnet 203 and pass the evaporation surface of the target 202.
Lines of magnetic force at high straightness are generated from the
evaporation surface of the target 202 to the direction of the
substrate in a wide region at the evaporation surface of the target
202. In other words, a great amount of lines of magnetic force
(vertical components) are generated in the wide region at the
evaporation surface of the target 202.
[0264] Then, FIG. 20 for the first exemplary invention and FIG. 23
for this exemplary invention are compared. In FIG. 20 and FIG. 23,
the range and the configuration of the distribution of lines of
magnetic force are substantially identical. However, in FIG. 23,
the straightness and the density of the lines of magnetic force
extending along the radial inside direction of the rear surface
magnet 204a and the rear surface magnet 204b and the lines of
magnetic force extending from both of the rear surface magnets
along the axis of the target 202 to the substrate 207 are higher
than those in the case of FIG. 20 in which the rear surface magnet
204 is disposed.
[0265] Also in FIG. 23, regions where the components of lines of
magnetic force vertical to the evaporation surface are not
substantially present are formed to the outer circumference of the
target 202 alike the regions indicated by the circles P in FIG. 20
for the first exemplary invention. Accordingly, also in this
exemplary invention, the disadvantage that arc spots move to the
outside of the evaporation surface of the target 202 beyond the
outer circumference of the target 202 can be avoided and the arc
spots can be retained on the evaporation surface of the target
202.
Third Embodiment
Third Invention
[0266] With reference to FIG. 24 and FIG. 25, a third embodiment of
the third invention is to be described.
[0267] FIG. 24 is a view illustrating a schematic constitution of
an arc evaporation source 201c according to the third embodiment of
the third invention (hereinafter referred to as an evaporation
source 201c). film deposition apparatus 206 according to this
embodiment is provided with the evaporation source 201c to be
described later instead of the evaporation source 201b according to
the second embodiment of the third invention. In the film
deposition apparatus 206 of this embodiment, other constitutions
than the evaporation source 201c are identical with those described
for the second embodiment of the third invention, and identical
constituent elements carry same reference numerals, for which
descriptions are to be omitted.
[0268] The evaporation source 201c in this embodiment comprises a
disk-shaped target 202 having a predetermined thickness and a
magnetic field forming unit 208c disposed near the target 202 in
the same manner as the evaporation source 201b in the second
embodiment of the third invention. The magnetic field forming unit
208c has a circumferential magnet 203, a rear surface magnet 204a,
and a rear surface magnet 204b in the same manner as the second
embodiment of the third invention and, further, comprises a single
magnetic body 209 in the radial inside of the rear surface magnet
204a and the rear surface magnet 204b.
[0269] The magnetic body 209 is a non-ring shaped magnetic core
which constitutes a core for the rear surface magnet 204a and the
rear surface magnet 204b. The magnetic body 209 is disposed so as
to penetrate the rear surface magnet 204a and the rear surface
magnet 204b, and has a disk-shape or circular columnar shape having
a diameter identical with the inner diameter of the rear surface
magnet 204a and the rear surface magnet 204b. The "non-ring shaped"
means not an annular shape in which an aperture is formed in the
radial inside like a doughnut but means a solid configuration such
as a disk shape or a circular cylindrical shape.
[0270] In other words, the rear surface magnet 204a and the rear
surface magnet 204b are disposed so as to surround the outer
circumference of one magnetic body 209 in close contact therewith.
In such an arrangement, the front end face of the rear surface
magnet 204a is substantially flush with the front end face of the
magnetic body 209, and the rear end face of the reference magnet
204b is substantially flush with the rear end face of the magnetic
body 209.
[0271] Summarizing the constitution of the evaporation source 201c,
it can be said that the target 202, the circumferential magnet 203,
the rear surface magnet 204a, a rear surface magnet 204b, and the
magnetic body 209 are disposed coaxially such that their axes are
aligned with each other.
[0272] As illustrated in FIG. 24, the inner circumferential
surfaces of the rear surface magnet 204a and the rear surface
magnet 204b are in close contact with the lateral surface of the
magnetic body 209. Thus, lines of magnetic force emitting from the
end faces of the rear magnet 204a and the rear magnet 204b can be
induced linearly through the magnetic body 209 in the axial
direction of the rear surface magnet 204a and the rear surface
magnet 204b.
[0273] Accordingly, in the magnetic body 209, repulsion of the
lines of magnetic force can be increased at a position near the
axes of the rear surface magnet 204a and the rear surface magnet
204b. As a result, a great amount of lines of magnetic force at
high straightness can be generated from the position near the axis
of the front end face of the magnetic body 209.
Third Exemplary Invention
Third Invention
[0274] With reference to FIG. 25, a distribution of lines of
magnetic force generated in the evaporation source 201c according
to a third embodiment of the third invention is to be described.
The distribution diagram of lines of magnetic force illustrated in
FIG. 25 shows a distribution of lines of magnetic force from the
back of the rear surface magnet 204b to the front surface of the
substrate 207. In the distribution diagram of lines of magnetic
force in FIG. 25, the right end indicates a position for the
surface of the substrate 207.
[0275] Various experimental conditions are shown below. For
example, the size of the target 202 is (100 mm diameter.times.16 mm
thickness). The size of the circumferential magnet 203 is (150 mm
inner diameter, 170 mm outer diameter, and 10 mm thickness) and the
distance of the circumferential magnet 203 from the surface of the
target 202 is 5 mm.
[0276] The size of the rear surface magnet 204a is (150 mm inner
diameter, 170 mm outer diameter, and 20 mm thickness) and the
distance from the surface of the target 2 to the rear surface
magnet 204a is 60 mm. The size of the rear surface magnet 204b is
(150 mm inner diameter, 170 mm outer diameter, and 20 mm
thickness), and the distance from the surface of the target 202 to
the rear surface magnet 204b is 90 mm. The distance between the
rear surface magnet 204a and the rear surface magnet 204b is 10
mm.
[0277] The size of the magnetic body 209 is (150 mm
diameter.times.50 mm height).
[0278] The magnetic field intensity at the surface of the target
202 is 150 gauss or more.
[0279] Referring to FIG. 25, a greater amount of lines of magnetic
force of high straightness emit from the rear surface magnet 204a
and the rear surface magnet 204b in a radial inside direction than
those in the case of the second exemplary invention illustrated in
FIG. 23. The lines of magnetic force extend substantially
vertically to the target 202 while changing the progressing
direction so as to be along the axial direction near the axis of
the magnetic body 209. The lines of magnetic force are combined
with the lines of magnetic force emitting from the circumferential
magnet 203 and pass the evaporation surface of the target 202.
Lines of magnetic force of higher straightness than those in the
second exemplary invention shown in FIG. 23 are generated from the
evaporation surface of the target 202 in a wide region at the
evaporation surface of the target 202 and extend in the direction
of the substrate. In other words, a great amount of vertical lines
of magnetic force (vertical components) are generated in the wide
region at the evaporation surface of the target 202.
[0280] FIG. 23 for the second exemplary invention and FIG. 25 for
this exemplary invention are compared. The range and the
configuration of the distribution for the lines of magnetic force
are substantially identical between FIG. 23 and FIG. 25. However,
the lines of magnetic force illustrated in FIG. 25 are concentrated
so as to converge further to the vicinity of the axes of the
magnetic body 209 and the target 202 than the lines of magnetic
force illustrated in FIG. 23. Accordingly, the straightness and the
density of the entire lines of magnetic force are increased more in
FIG. 25 than those in FIG. 23.
[0281] Further, also in FIG. 25, regions in which the components of
lines of magnetic force vertical to the evaporation surface are not
substantially present are formed to the outer circumference of the
target 202 in the same manner as in FIG. 23 for the second
exemplary invention described above. Accordingly, also in this
exemplary invention, the disadvantage that arc spots move to the
outside of the evaporation surface of the target 202 beyond the
outer circumference of the target 202 can be avoided and the arc
spots can be retained on the evaporation surface of the target
202.
[0282] The target 202 is not restricted to the disk-shaped shape
but may also be a polygonal, for example, tetragonal shape.
Further, the circumferential magnet 203 and the rear surface
magnets 204a and 204b are not restricted to the toroidal shape but
may also be an annular polygonal, for example, tetragonal
shape.
[0283] By the way, it should be understood that each of the
embodiments of the present invention disclosed herein is only for
illustration but not limitative in all respects. Particularly,
values for those matters not disclosed explicitly in each of the
embodiments, for example, operation conditions measuring
conditions, various parameters, and size, weight and volume of
constituent components, do not depart the range usually practiced
by persons skilled in the art and values that can be usually
estimated easily by the persons skilled in the art are adopted.
[0284] While expression such as parallel, crossing and identical
and, in addition, an expression of coaxial are used with respect to
the shape and the size of each of constituent elements, for
example, in the description for the evaporation source in each of
the embodiments of the invention, they are not strictly defined
with a mathematical point of view. Errors within such a range that
they can be considered as parallel, crossing, identical and coaxial
in usual fabrication accuracy for machinery parts are naturally
tolerable.
[0285] While the present invention has been described with respect
to the embodiments and the examples, the present invention is not
restricted to the embodiments described above but can be modified
and practiced within the extent described in the range of the scope
of the claims. The present application is based on Japanese Patent
Application filed on Feb. 23, 2011 (Japanese Patent Application No.
2011-037094), Japanese Patent Application filed on Feb. 23, 2011
(Japanese Patent Application No. 2011-037095), Japanese Patent
Application filed on Apr. 25, 2011 (Japanese Patent Application No.
2011-097162), Japanese Patent Application filed on May 26, 2011
(Japanese Patent Application No. 2011-118267), and Japanese Patent
Application filed on Aug. 22, 2011 (Japanese Patent Application No.
2011-180544), and the contents thereof are herein incorporated for
the reference.
INDUSTRIAL APPLICABILITY
[0286] The present invention is applicable to an arc evaporation
source for a film deposition apparatus that forms thin films.
LIST OF REFERENCE SIGNS
[0287] 1, 101, 201a to 201c evaporation source (arc evaporation
source) [0288] 2, 102, 202 target [0289] 3, 103, 203
circumferential magnet [0290] 6, 106, 206 film deposition apparatus
[0291] 7, 107, 207 substrate [0292] 8, 108, 208a to 208c magnetic
field forming unit [0293] 9, 109, 110 solenoid coil [0294] 11, 111,
211 vacuum chamber [0295] 12, 112, 212 rotary table [0296] 13, 113,
213 gas introduction port [0297] 14, 114, 214 gas exhaust port
[0298] 15, 115, 215 arc power source [0299] 16, 116, 216 bias power
source [0300] 18, 118, 218 ground [0301] 104, 204a, 204b rear
surface magnet [0302] 104A first permanent magnet (disk-shaped rear
surface magnet) [0303] 104B second permanent magnet (disk-shaped
rear surface magnet) [0304] 105 magnetic core [0305] 220 rear
surface electro magnet
* * * * *