U.S. patent application number 16/897762 was filed with the patent office on 2020-09-24 for heat-transfer roller for sputtering and method of making the same.
This patent application is currently assigned to KEIHIN RAMTECH CO., LTD.. The applicant listed for this patent is Keihin Ramtech Co., Ltd.. Invention is credited to Keiichi HASHIMOTO, Hiroshi IWATA, Toshiyuki NEDU, Naoya OKADA, Ippei SATO, Naonori SHIBATA, Yuta TAKAKUWA.
Application Number | 20200303173 16/897762 |
Document ID | / |
Family ID | 1000004882414 |
Filed Date | 2020-09-24 |
View All Diagrams
United States Patent
Application |
20200303173 |
Kind Code |
A1 |
IWATA; Hiroshi ; et
al. |
September 24, 2020 |
HEAT-TRANSFER ROLLER FOR SPUTTERING AND METHOD OF MAKING THE
SAME
Abstract
This sputtering cathode has a sputtering target having a tubular
shape in which the cross-sectional shape thereof has a pair of long
side sections facing each other, and an erosion surface facing
inward. Using the sputtering target, while moving a body to be
film-formed, which has a film formation region having a narrower
width than the long side sections of the sputtering target,
parallel to one end face of the sputtering target and at a constant
speed in a direction perpendicular to the long side sections above
a space surrounded by the sputtering target, discharge is performed
such that a plasma circulating along the inner surface of the
sputtering target is generated, and the inner surface of the long
side sections of the sputtering target is sputtered by ions in the
plasma generated by a sputtering gas to perform film formation in
the film formation region of the body to be film-formed.
Inventors: |
IWATA; Hiroshi;
(Kamakura-shi, JP) ; NEDU; Toshiyuki;
(Kamakura-shi, JP) ; TAKAKUWA; Yuta;
(Kamakura-shi, JP) ; OKADA; Naoya; (Kamakura-shi,
JP) ; SATO; Ippei; (Kamakura-shi, JP) ;
SHIBATA; Naonori; (Kamakura-shi, JP) ; HASHIMOTO;
Keiichi; (Kamakura-shi, JP) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
Keihin Ramtech Co., Ltd. |
Kamakura-shi |
|
JP |
|
|
Assignee: |
KEIHIN RAMTECH CO., LTD.
|
Family ID: |
1000004882414 |
Appl. No.: |
16/897762 |
Filed: |
June 10, 2020 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
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16297121 |
Mar 8, 2019 |
10692708 |
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16897762 |
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15735847 |
Dec 12, 2017 |
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PCT/JP2017/002463 |
Jan 25, 2017 |
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16297121 |
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Current U.S.
Class: |
1/1 |
Current CPC
Class: |
C23C 14/562 20130101;
H01J 37/342 20130101; H01J 37/3423 20130101; C23C 14/3407 20130101;
C23C 14/35 20130101; H01J 37/3452 20130101; H01J 37/345
20130101 |
International
Class: |
H01J 37/34 20060101
H01J037/34; C23C 14/35 20060101 C23C014/35; C23C 14/34 20060101
C23C014/34 |
Foreign Application Data
Date |
Code |
Application Number |
Mar 30, 2016 |
JP |
2016-067068 |
Aug 31, 2016 |
JP |
2016-168705 |
Claims
1. A cylindrical heat-transfer roller for cooling or heating an
item passing around the roller, comprising: a cylinder wall
encircling a hollow interior of the roller and having two opposite
ends; an end plate attached to each of the two ends of the cylinder
wall; and a centrally located shaft member extending from each end
plate to support the roller for rotation about a longitudinally
extending central axis of the roller; wherein one or more
flow-through passages are embedded within the cylinder wall and
provide a conduit or conduits through which a heat-transfer medium
can flow from near one end of the cylinder wall to the other end of
the cylinder wall; wherein each of the shaft members has a
longitudinally extending central passage that is in fluid
communication with the one or more flow-through passages in the
cylinder wall near a respective one of the two ends of the cylinder
wall; and wherein through-holes are formed in the end plates so
that the hollow interior of the roller is in fluid communication
with exterior regions surrounding the roller, whereby pressure can
be equalized between the hollow interior of the roller and the
exterior regions surrounding the roller.
2. The heat-transfer roller of claim 1, wherein the one or more
flow-through passages embedded within the cylinder wall comprises a
single conduit extending in a zig-zag or serpentine manner from
near one end of the cylinder wall to the other end of the cylinder
wall, with a series of first portions that extend in a first
direction and that are arranged parallel to each other and a series
of second portions that extend in a second direction that is
perpendicular to the first direction, with the second portions each
extending between a respective adjacent pair of the first portions
and with successive ones of the second portions being located at
alternating ends of the first portions.
3. The heat-transfer roller of claim 2, further comprising a pipe
near each end of the roller and disposed within the hollow interior
of the roller, with each pipe connecting the longitudinally
extending central passage in one of the shaft members to a
corresponding end of the single conduit extending in zig-zag or
serpentine fashion.
4. The heat-transfer roller of claim 2, wherein the first direction
is a circumferential direction with respect to the roller and the
second direction is a longitudinal direction with respect to the
roller that is parallel to the longitudinally extending central
axis of the roller.
5. The heat-transfer roller of claim 2, wherein the first direction
is a longitudinal direction with respect to the roller that is
parallel to the longitudinally extending central axis of the roller
and the second direction is a circumferential direction with
respect to the roller.
6. The heat-transfer roller of claim 2, wherein the single conduit
is constituted by a groove with a zig-zagging shape that extends
along a surface of the cylinder wall and a closure plate with a
shape that matches the zig-zagging shape of the groove, with the
conduit being bounded by wall surfaces of the groove, a bottom
surface of the groove, and the closure plate.
7. The heat-transfer roller of claim 6, wherein the closure plate
has been joined to the wall surfaces of the groove by friction stir
welding.
8. The heat-transfer roller of claim 6, further comprising one or
more props disposed within the groove to support the closure
plate.
9. The heat-transfer roller of claim 8, wherein the props comprise
corner blocks located at junctions between the wall surfaces of the
groove and the bottom surface of the groove, which corner blocks
form shoulder surfaces against which the closure plate bears.
10. The heat-transfer roller of claim 1, wherein the one or more
flow-through passages embedded within the cylinder wall comprises a
plurality of passages that are arranged parallel to each other and
that extend from one end of the cylinder wall to the other end of
the cylinder wall in a longitudinal direction with respect to the
roller that is parallel to the longitudinally extending central
axis of the roller.
11. The heat-transfer roller of claim 1, wherein the cylinder wall
has a longitudinally extending seam, where edges of a plate that
has been curved to form the cylinder wall have been joined
together.
12. The heat-transfer roller of claim 11, wherein the seam has been
formed by friction stir welding.
13. The heat-transfer roller of claim 1, wherein a plurality of
through-holes are formed in the end plate at each end of the
cylinder wall and the through-holes in each end plate are
equiangularly positioned around the longitudinally extending
central axis of the roller.
14. The heat-transfer roller of claim 1, wherein the cylinder wall
is made from copper, copper alloy, aluminum, or aluminum alloy.
15. The heat-transfer roller of claim 14, wherein the cylinder wall
is made from oxygen-free copper, tough pitch copper, or phosphorous
deoxidized copper.
16. The heat-transfer roller of claim 14, wherein the cylinder wall
is made from a copper-tin-based alloy, a coper-zinc-based alloy, a
copper-nickel-based alloy, a copper-aluminum-based alloy, or a
copper-beryllium-based alloy.
17. The heat-transfer roller of claim 14, wherein the cylinder wall
is made from an aluminum-copper-magnesium-based alloy, an
aluminum-manganese-based alloy, an aluminum-silicon-based alloy, an
aluminum-magnesium-based alloy, an aluminum-magnesium-silicon-based
alloy, or an aluminum-zinc-magnesium-based alloy.
18. The heat-transfer roller of claim 1, further comprising a
coating layer disposed on an exterior-facing surface of the
cylinder wall, the coating layer being formed from a material
having a hardness higher than the material from which the cylinder
wall is made.
19. The heat-transfer roller of claim 18, wherein the cylinder wall
is made from copper, copper alloy, aluminum, or aluminum alloy and
the coating layer is made from chromium.
20. The heat-transfer roller of claim 18, wherein the coating layer
is not less than 20 .mu.m thick and not greater than 40 .mu.m
thick.
21. The heat-transfer roller of claim 18, where the coating layer
has a Vickers hardness that is not less than 500.
22. (canceled)
23. A sputtering system, comprising: a vacuum chamber; a
heat-transfer roller according to claim 1 disposed within the
vacuum chamber and supported for rotation about the longitudinally
extending central axis thereof; one or more sputtering cathodes
disposed within the vacuum chamber and arranged to direct sputtered
atoms toward the heat-transfer roller during sputtering operation
of the one or more sputtering cathodes; and a film supply roller
and a film take-up roller disposed within the vacuum chamber, with
the film supply roller and the film take-up roller having
respective longitudinal axes that are arranged parallel to the
longitudinally extending central axis of the heat-transfer roller
and with the film supply roller and the film take-up roller being
supported for rotation about their respective longitudinal
axes.
24. The sputtering system according to claim 23, wherein the vacuum
chamber has a perforated partition that divides the vacuum chamber
into two sub-chambers, with the heat-transfer roller and the one or
more sputtering cathodes being disposed within one of the two
sub-chambers and with the film supply roller and the film take-up
roller being disposed within the other of the two sub-chambers.
25. A method of forming a heat-transfer roller, comprising; forming
one or more flow-through passages extending internally within a
square or rectangular metal plate; curving the square or
rectangular metal plate to form a cylinder wall with a hollow
interior and a longitudinally extending central axis, and joining
first and second, opposite edges of the square or rectangular metal
plate together using friction stir welding; attaching an end plate
to each of two opposite ends of the cylinder wall; attaching a
shaft member to each of the two end plates in position to support
the roller for rotation about the longitudinally extending central
axis of the cylinder wall; forming a longitudinally extending
central passage within each of the two shaft members; establishing
fluid communication between the longitudinally extending central
passage in each of the two shaft members and the one or more
flow-through passages in the square or rectangular metal plate; and
forming through-holes in the end plates so that the hollow interior
of the cylinder wall is in fluid communication with exterior
regions surrounding the cylinder wall, whereby pressure can be
equalized between the hollow interior of the cylinder wall and the
exterior regions surrounding the cylinder wall.
26. The method according to claim 25, wherein said forming one or
more flow-through passages extending internally within the square
or rectangular metal plate comprises forming in a surface of the
square or rectangular metal plate a single continuous groove
extending in a zig-zag or serpentine manner, with a series of first
portions that extend in a first direction and that are arranged
parallel to each other and a series of second portions that extend
in a second direction that is perpendicular to the first direction,
with each of the second portions extending between a respective
adjacent pair of the first portions and with successive ones of the
second portions being located at alternating ends of the first
portions; forming a closure plate having a zig-zag or serpentine
shape that matches the zig-zag or serpentine shape of the single
continuous groove; disposing the closure plate within the single
continuous groove, positioned at a distance from a bottom surface
of the single continuous groove and with an exterior-facing surface
of the closure plate flush with the surface of the square or
rectangular metal plate; and joining the closure plate to the
square or rectangular metal plate along joints therebetween by
friction stir welding.
27. The method according to claim 26, wherein the single continuous
groove is formed by forming an initial groove in the surface of the
square or rectangular metal plate and then forming a subsequent
groove that is wider than the initial groove and that extends into
the surface of the square or rectangular metal plate to a depth
that is shallower than the depth to which the initial groove
extends into the surface of the square or rectangular metal plate,
whereby a shoulder surface to support the closure plate is
formed.
28. The method according to claim 26, wherein the square or
rectangular metal plate is curved about a linear center of
curvature that extends in a direction that is perpendicular to the
first portions of the single continuous groove such that the first
portions of the single continuous groove extend circumferentially
about the cylinder wall and the second portions of the single
continuous groove extend in direction that is parallel to the
longitudinally extending central axis of the cylinder wall once the
first and second edges of the square or rectangular metal plate are
joined together.
29. The method according to claim 26, wherein the square or
rectangular metal plate is curved about a linear center of
curvature that extends in a direction that is parallel to the first
portions of the single continuous groove such that the first
portions of the single continuous groove extend in direction that
is parallel to the longitudinally extending central axis of the
cylinder wall and the second portions of the single continuous
groove extend circumferentially along the cylinder wall once the
first and second edges of the square or rectangular metal plate are
joined together.
30. The method according to claim 25, wherein said forming one or
more flow-through passages extending internally within the square
or rectangular metal plate comprises forming holes extending
internally through the square or rectangular metal plate from a
third edge thereof to an opposite, fourth edge thereof, with the
holes extending parallel to the first and second edges of the
square or rectangular metal plate.
31. The method according to claim 30, wherein the holes extending
internally through the square or rectangular metal plate are formed
after the first and second edges of the square or rectangular metal
plate have been joined together.
Description
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application is a continuation of U.S. application Ser.
No. 16/297,121 filed Mar. 8, 2019, the contents of which are
incorporated by reference and all benefits of which are claimed.
That application was a continuation of U.S. application Ser. No.
15/735,847 filed Dec. 12, 2017, the contents of which are
incorporated by reference and all benefits of which are claimed.
That application, in turn, was a National Stage Entry of
PCT/JP2017/002463 filed Jan. 25, 2017, the contents of which are
incorporated by reference and all benefits of which are claimed.
The PCT application is based on JP 2016-067068 filed Mar. 30, 2016
and 2016-168705 filed Aug. 31, 2016, the contents of both of which
are incorporated by reference and all benefits of both of which are
claimed.
BACKGROUND OF THE INVENTION
Technical Field
[0002] This invention relates to a sputtering cathode, a sputtering
device, and a method for producing a film-formed body, which are
suitably applied to make various devices in which thin films are
formed by a sputtering method.
Background Art
[0003] Heretofore, in steps for forming electrodes in various
devices such as semiconductor devices, solar batteries, liquid
crystal displays, organic ELs, vacuum evaporation devices have been
used to deposit electrode materials. However, a vacuum evaporation
method has difficulties in controlling distribution of film
thickness spatially and in time. Therefore, deposition of electrode
materials by a sputtering method is desired.
[0004] Heretofore, as sputtering devices, a parallel-plate,
magnetron sputtering device, an RF sputtering device, a facing
targets sputtering device, etc. have been known. Among them, in the
facing targets sputtering device, two circular or square or
rectangular targets made of the same materials having the same size
are faced parallel to each other and film formation is performed by
sputtering the targets by introducing a sputtering gas into a space
between the targets and performing discharge (for example, see
non-patent literatures 1.about.3). It is said that the facing
targets sputtering device can perform high vacuum, low voltage
discharge by restricting a plasma in a space between the two
targets, which can stand comparison with plasma restriction in the
magnetron sputtering device, and realize generation of sputtering
particles, and further prevent a neutral reflected process gas from
bombarding the surface of a substrate to be film-formed by
restricting the plasma with formation of magnetic field in the
plasma space.
[0005] On the other hand, another spettering device has been known
(see patent literature 1). In the sputtering device, a ringlike
sputtering target is used, a string or cylindrical body to be
film-formed is moved in the axial direction of a sputtering space
inside the ringlike sputtering target, or the body to be
film-formed is fixed in the axial direction in the sputtering space
and film formation is performed on the body to be film-formed by
performing sputtering.
PRIOR ART LITERATURE
Patent Literature
[0006] [PATENT LITERATURE 1] Laid-open patent gazette
2009-256698
[PATENT LITERATURE 2] Gazette of Patent No. 5102470
Non-Patent Literature
[0007] [NON-PATENT LITERATURE 1] J. Vac. Soc. Jpn. Vol. 44, No. 9,
2001, pp. 808-814 [NON-PATENT LITERATURE 2] Journal of the
department of engineering of Tokyo Polytechnic University, Vol. 30
No. 1 (2007) pp. 51-58
[NON-PATENT LITERATURE 3] ULVAC TECHNICAL JOURNAL No. 64 2006, pp.
18-22
SUMMARY OF THE INVENTION
Subjects to be Solved by Invention
[0008] However, the facing targets sputtering device described
above has a drawback that the plasma density between the facing two
targets is low and sufficiently high deposition rate cannot be
obtained.
[0009] On the other hand, the sputtering device proposed in patent
literature 1 has a drawback that it is difficult to perform film
formation on a flat boardlike body to be film-formed.
[0010] Therefore, the subject to be solved by the invention is to
provide a sputtering cathode, a sputtering device, and a method for
producing a film-formed body which can perform film formation on a
flat boardlike or filmlike body to be film-formed at a sufficiently
high deposition rate and with low bombardment.
Means to Solve the Subjects
[0011] To solve the above subject, according to the invention,
there is provided a sputtering cathode, comprising:
[0012] a sputtering target having a tubular shape in which the
cross-sectional shape thereof has a pair of long side sections
facing each other, an erosion surface facing inward.
[0013] Further, according to the invention, there is provided a
sputtering device, comprising:
[0014] a sputtering cathode, comprising a sputtering target having
a tubular shape in which the cross-sectional shape thereof has a
pair of long side sections facing each other, an erosion surface
facing inward; and
[0015] an anode disposed such that the erosion surface of the
sputtering target is exposed,
[0016] wherein while moving a body to be film-formed having a film
formation region having a narrower width than the long side
sections of the sputtering target in a direction traversing the
long side sections of the sputtering target for the sputtering
target at a constant speed above a space surrounded by the
sputtering target, discharge is performed such that a plasma
circulating along the inner surface of the sputtering target is
generated, and the inner surface of the long side sections of the
sputtering target is sputtered by ions in the plasma generated by a
sputtering gas to perform film formation in the film formation
region of the body to be film-formed.
[0017] Further, according to the invention, there is provided a
method for producing a film-formed body, comprising:
[0018] using a sputtering cathode, comprising: a sputtering target
having a tubular shape in which the cross-sectional shape thereof
has a pair of long side sections facing each other, an erosion
surface facing inward, performing discharge such that a plasma
circulating along the inner surface of the sputtering target is
generated, and the inner surface of the long side sections of the
sputtering target is sputtered by ions in the plasma generated by a
sputtering gas to perform film formation in a film formation region
having a narrower width than the long side sections of the
sputtering target of a body to be film-formed while moving the body
to be film-formed in a direction traversing the long side sections
of the sputtering target for the sputtering target at a constant
speed above a space surrounded by the sputtering target.
[0019] In the inventions, typically, the distance between the pair
of long side sections facing each other of the sputtering target is
preferably not less than 50 mm and not larger than 150 mm, more
preferably not less than 60 mm and not larger than 100 mm, most
preferably not less than 70 mm and not larger than 90 mm in order
to obtain the sufficient number of sputtered particles going toward
a space above the sputtering target and to prevent light generated
from the plasma generated near the surface of the sputtering target
from irradiating the body to be film-formed which moves in the
space above the sputtering target, when the sputtering cathode is
attached to the sputtering device and used. Furthermore, the ratio
of the length of the long side section to the distance between the
pairs of long side sections of the sputtering target is typically
not less than 2 and preferably not less than 5. Although there is
no upper limit of the ratio, the ratio is generally not larger than
40.
[0020] The pair of the long side sections of the sputtering target
are typically parallel to each other, but not limited to this and
they may slant each other. The cross-sectional shape of the
sputtering target typically has the pair of long side sections
which are parallel to each other and a pair of short side sections
facing each other perpendicular to the long side sections. In this
case, the sputtering target has a shape like a rectangular pipe
having the rectangular cross-sectional shape. The cross-sectional
shape of the sputtering target may have both ends in a direction
parallel to the long side sections composed of a pair of outwardly
convex curved sections (for example, semicircular sections) facing
each other. The sputtering target having the shape like a
rectangular pipe having the rectangular cross-sectional shape
typically comprises a first flat board and a second flat board
forming the pair of long side sections and a third flat board and a
fourth flat board forming the pair of short side sections facing
each other perpendicular to the long side sections. In this case,
the sputtering target can be assembled by separately making the
first to fourth flat boards and arranging them like a rectangular
pipe. The first flat board and the second flat board forming the
pair of long side sections are generally made of materials with the
same composition as materials to be deposited, but may be composed
of materials different from each other. For example, the first flat
board is made of material A and the second flat board is made of
material B. And by applying a beam of sputtered particles from the
first flat board and a beam of sputtered particles from the second
flat board to the body to be film-formed, a thin film composed of A
and B can be formed. If necessary, by using two or more components
material as materials A and B, a thin film made of multicomponent
materials can be formed. More specifically, for example, by making
the first flat board of metal M.sub.1 composed of single element
and making the second flat board of metal M.sub.2 composed of
single element, a binary alloy thin film composed of M.sub.1 and
M.sub.2 can be formed. This means that a film formation method
similar to a binary evaporation method in a vacuum evaporation
method can be realized by the sputtering device. Furthermore, it is
possible to form a two-layer structure thin film made of a thin
film composed of A and a thin film composed of B formed thereon as
follows. That is, for example, a shield plate, which is capable of
inserting and pulling out, is inserted between the body to be
film-formed and the sputtering target, so that, for example, the
beam of sputtered particles from the second flat board is shielded.
And by applying the beam of sputtered particles from the first flat
board to the body to be film-formed while the body is moved, the
thin film composed of A is first formed on the body to be
film-formed. Then the beam of sputtered particles from the first
flat board is shielded. And by applying the beam of sputtered
particles from the second flat board to the body to be film-formed
while the body to be film-formed is moved in the reverse direction,
the thin film composed of B is formed on the body to be
film-formed.
[0021] Generally, the beam of sputtered particles from sections of
the sputtering target except the pair of long side sections is not
positively used for film formation. However, in order to prevent
unintentional elements from mixing, the sections of the sputtering
target except the pair of long side sections are typically made of
similar materials as the long side sections. However, when the beam
of sputtered particles from the sections of the sputtering target
except the pair of long side sections are positively used for film
formation, the sections of the sputtering target except the pair of
long side sections may be made of materials different from the pair
of long side sections.
[0022] It is possible to obtain the beam of sputtered particles
from the sputtering target not only above the space surrounded by
the sputtering target but also below the space. Therefore, if
necessary, it is possible to move another body to be film-formed
below the space surrounded by the sputtering target for the
sputtering target at a constant speed in a direction traversing the
long side sections of the sputtering target and form a film in the
film formation region of the body to be film-formed during that
time.
[0023] By the way, heretofore, in a sputtering device in which film
formation is performed on a film by a roll-to roll method, a film
formation roller (also called a main roller) is disposed in a
deposition chamber and a pair of rollers for unwinding/winding is
disposed in a film carrying chamber which is disposed separately
from the deposition chamber. And while a film is unwound from one
roller of the pair of rollers and the film is wound by the other
roller through the film formation roller, film formation is
performed on the film wound by the film formation roller. The film
formation roller which has been generally used heretofore is formed
by a cylindrical stainless steel plate. Another cylindrical
stainless steel plate is disposed inside the cylindrical stainless
steel plate. And cooling water is poured into a space between the
double stainless steel plate, so that the film formation roller can
be cooled. However, since the film formation roller has a structure
in which pressure by cooling water is applied to the whole inner
surface of the outer cylindrical stainless steel plate, it has
drawbacks that the outer cylindrical stainless steel plate is
deformed like a beer barrel in vacuum and therefore not only the
surface of the film is curved but also the film cannot be carried
smoothly.
[0024] The drawbacks can be eliminated by using a film formation
roller having a cylindrical section made of copper, copper alloy,
aluminum or aluminum alloy having a built-in flow passage at least
in an effective section thereof as the film formation roller around
which a body to be film-formed on which film formation is performed
by a roll-to-roll method is wound. Here, the effective section of
the film formation roller means the section around which the body
to be film-formed is wound and with which the body to be
film-formed comes in contact. The body to be film-formed may be
anything and not limited particularly as far as it can be wound
around the effective section of the film formation roller.
Specifically, the body to be film-formed is, for example, a film, a
sheet, a clothlike body composed of fibers, etc. and its material
may be various materials such as resins, metal materials
(iron-based materials and nonferrous materials) such as single
metal, alloy, etc. When the cylindrical section is made of copper
or copper alloy, if thermal conductivity and workability are
regarded as most important, the cylindrical section is preferably
made of copper (pure copper) (for example, oxygen-free copper,
tough pitch copper, phosphorus deoxidized copper, etc.) having high
thermal conductivity and high ductility, most preferably
oxygen-free copper. On the other hand, the cylindrical section is
made of copper alloy when characteristics which cannot be obtained
by copper (for example, mechanical strength higher than that of
copper) are necessary. As copper alloy, copper-tin based alloy,
copper-zinc based alloy, copper-nickel based alloy, copper-aluminum
based alloy, copper-beryllium based alloy, etc. are exemplified,
and alloy and its composition satisfying characteristics demanded
for the cylindrical section are selected among them. Furthermore,
when the cylindrical section is made of aluminum or aluminum alloy,
if thermal conductivity and workability are regarded as most
important, the cylindrical section is preferably made of aluminum
(pure aluminum) having high thermal conductivity and high
ductility. On the other hand, the cylindrical section is made of
aluminum alloy when characteristics which cannot be obtained by
aluminum (for example, mechanical strength higher than that of
aluminum) are necessary. As aluminum alloy,
aluminum-copper-magnesium based alloy, aluminum-manganese based
alloy, aluminum-silicon based alloy, aluminum-magnesium based
alloy, aluminum-magnesium-silicon based alloy,
aluminum-zinc-magnesium based alloy, etc. are exemplified, and
alloy and its composition satisfying characteristics demanded for
the cylindrical section are selected among them. By making the
cylindrical section of copper, copper alloy, aluminum or aluminum
alloy, it is possible to obtain thermal conductivity higher than
that of stainless steel at least. For example, thermal conductivity
of stainless steel is 16.7 W/(mK) for SUS304 and SUS316 and 26.0
W/(mK) for SUS444. In contrast with this, thermal conductivity of
copper is 391 W/(mK) for oxygen-free copper (C1020) and tough pitch
copper (C1100) and 339 W/(mK) for phosphorus deoxidized copper.
Thermal conductivity of copper alloy is 121 W/(mK) for class 1
brass which is copper-zinc based alloy, 33 W/(mK) for class 2
nickel silver which is copper-nickel based alloy, 84 W/(mK) for
class 1 phosphor bronze which is copper-tin based alloy, 210 W/(mK)
for copper-nickel-silicon alloy (Corson alloy) which is
copper-nickel based alloy, for example, EFTEC23Z. Thermal
conductivity of aluminum is 220 W/(mK) for A1100. Thermal
conductivity of aluminum alloy is 190 W/(mK) for A2017 which is
aluminum-copper-magnesium based alloy, 190 W/(mK) for A3003 which
is aluminum-magnesium based alloy, 150 W/(mK) for A4032 which is
aluminum-silicon based alloy, 200 W/(mK) for A5005 which is
aluminum-magnesium based alloy, 220 W/(mK) for A6063 which is
aluminum-magnesium-silicon based alloy, and 130 W/(mK) for A7075
which is aluminum-zinc-magnesium based alloy. Above thermal
conductivity of copper, copper alloy, aluminum and aluminum alloy
is higher than that of stainless steel.
[0025] Preferably, formed on at least the outer peripheral surface
of the cylindrical section made of copper, copper alloy, aluminum
or aluminum alloy is a coating layer made of material having
hardness higher than that of copper, copper alloy, aluminum or
aluminum alloy forming the cylindrical section. For example,
plating of material with hardness higher than that of copper,
copper alloy, aluminum or aluminum alloy, preferably hard chromium
is performed on the surface of the cylindrical section. The
thickness of the coating layer or plating layer is selected so as
not to lower thermal conductivity of the surface of the cylindrical
section.
[0026] Fluid such as liquid or gas is poured into the flow passage
built in the cylindrical section, and what fluid is poured is
determined appropriately according to kind of material forming the
cylindrical section etc. Water, oil, alternative chlorofluorocarbon
(hydro fluorocarbon (HFC)), air, etc. are exemplified as fluid. The
flow passage built in the cylindrical section typically has a
zigzag folded shape having a section elongating linearly in the
circumferential direction of the cylindrical section (when the
cylindrical section is expanded in a plane, it becomes a linear
part) and a turn back section. The cross-sectional shape of the
flow passage is not particularly limited and appropriately
selected. The cross-sectional shape of the flow passage is
preferably a rectangular cross-sectional shape parallel to the
central axis of the cylindrical section. In more detail, the
cylindrical section is preferably formed by a cylinder made by
rounding a flat board having a rectangular or square planar shape
in a direction parallel to one side of the flat board (a direction
parallel to the linear part or the vertical direction to the linear
part of the flow passage when the cylindrical section is expanded
in a plane) and joining one end and the other end of the rounded
board, the flat board being formed by a first flat board having the
same rectangular or square planar shape as a planar shape obtained
by expanding the cylindrical section in a plane, a groove
comprising a lower groove having the same planar shape as the flow
passage obtained by expanding the cylindrical section in a plane
and an upper groove larger than the lower groove having a planar
shape almost similar to the lower groove being provided on one
major surface of the first flat board and a second flat board put
in the upper groove of the groove of the first flat board, a
boundary section of the first flat board and the second flat board
being joined by friction stir welding. When the flat board is
rounded like a cylinder in the direction parallel to its one side,
the surface of the flat board on the side of the boundary section
between the first flat board and the second flat board joined by
friction stir welding may face outward or inward. When the flat
board is rounded like a cylinder, a prop for supporting the second
flat board put in the upper groove of the groove of the first flat
board may be formed inside the lower groove in order to prevent
that the lower groove, which finally forms the flow passage,
becomes deformed and the flow passage having the cross-sectional
shape as designed cannot be obtained. With this, since the prop
supports the second flat board for the lower groove when the flat
board is rounded like a cylinder, it is possible to prevent the
lower groove from deforming. The prop may be formed at at least one
place, typically several places, or formed like a line or points
along the whole lower groove depending on the situation in the
elongation direction of the lower groove. The width of the prop is
preferably selected to be sufficiently small compared with the
width of the lower groove so as not to reduce the area of the cross
section of the lower groove too much. The prop may be formed as one
body with the first flat board or the second flat board, or may be
formed separately from the first flat board and the second flat
board. Friction stir welding is a solid phase welding using
friction heat and plastic flow. According to friction stir welding,
a welding tool is inserted into material and the welding tool is
moved along the welding line while the welding tool is rotated, so
that the material is softened by friction heat generated between
the welding tool and the material and stirred by the welding tool
and finally welded (for example, see patent literature 2.).
Crystalline structure obtained by the friction stir welding becomes
more fine compared with that before welding, and ductility in a
direction along the welding line is improved. Therefore, since the
flat board having the rectangular or square planar shape in which
the boundary section between the first flat board and the second
flat board is joined by friction stir welding has good ductility in
the direction of the boundary section, it is possible to easily
round the flat board in the direction of the boundary section so
that the surface of the flat board on the side of the boundary
section of the first flat board and the second flat board joined by
friction stir welding faces outward without resulting breakdown or
damage of the boundary section of the first flat board and the
second flat board. The flow passage built in the cylindrical
section is not limited to the flow passage having the zigzag folded
shape having a section elongating linearly in the circumferential
direction of the cylindrical section and a turn back section and
may be, for example, a flow passage having a zigzag folded shape
having a section elongating in a direction parallel to the central
axis of the cylindrical section and a turn back section.
Furthermore, the flow passage built in the cylindrical section may
be flow passages formed between both ends of the cylindrical
section parallel to the central axis of the cylindrical section and
at a plurality of places in equal intervals in the circumferential
direction of the cylindrical section. Such flow passages can be
formed by, for example, rounding a flat board having the same
rectangular or square planar shape as the planar shape obtained by
expanding the cylindrical section in a plane in a direction
parallel to one side of the flat board like a cylinder, joining one
end and the other end of the rounded board and forming throughholes
extending from one end to the other end of the rounded board. The
cross-sectional shape of the flow passages in this case is not
particularly limited, and is a circle when the throughholes are
formed by, for example, gun drilling.
[0027] Typically, a circular board is attached to each end of the
cylindrical board such as to close the cylindrical section and each
circular board has throughholes communicating the inside and the
outside of the cylindrical section. With this, when the film
formation roller is disposed in the deposition chamber and the
deposition chamber is evacuated, it is possible to equalize
pressure of the inside and the outside of the cylindrical section
to prevent the cylindrical section from being deformed by
application of external force. Material forming the circular board
is selected appropriately and, for example, stainless steel. In
order to obtain symmetry of weight distribution around the central
axis of the film formation roller and rotate the film formation
roller smmothly, the throughholes of the circular board are
preferably arranged symmetrically around the central axis of the
circular board. Typically, a shaft is attached to the outside of
each circular board on the central axis of the film formation
roller, therefore the cylindrical section. Supply of fluid into the
flow passage built in the cylindrical section is performed, for
example, as follows. That is, a first throughhole is formed on the
central axis of one shaft so as to go through the shaft and one
circular board, a second throughhole is formed on the central axis
of the other shaft so as to go through the other shaft and the
other circular board, one end of a first pipe is hermerically fixed
inside the cylindrical section so as to communicate with the first
throughhole, the other end of the first pipe is hermetically
connected with a hole formed on one end part of the flow passage
built in the cylindrical section on the side of the one circular
board so as to communicate with the flow passage, one end of a
second pipe is hermetically fixed inside the cylindrical section so
as to communicate with the second throughhole and the other end of
the second pipe is hermetically connected with a hole formed on the
other end of the flow passage built in the cylindrical section on
the side of the other circular board so as to communicate with the
flow passage. And fluid is supplied from the outside through the
first throughhole of the one shaft. Fluid is then supplied through
the first pipe to one end of the flow passage built in the
cylindrical section. And fluid is discharged to the outside from
the second throughhole of the other shaft through the other end of
the flow passage and the second pipe connected with the other end.
In this way, fluid circulates in the flow passage. Or, a third
throughhole is formed on the central axis of one shaft so as to go
through the one shaft, a fourth throughhole is formed on the
central axis of the other shaft so as to go through the other
shaft, a flow passage is formed inside the one circular board so as
to communicate with the third throughhole, the flow passage
communicates with one end part of the flow passage built in the
cylindrical section on the side of the other circular board, a flow
passage is formed inside the other circular board so as to
communicate with the fourth throughhole and the flow passage
communicates with the other end part of the flow passage built in
the cylindrical section on the side of the other circular board.
And, fluid is supplied from the outside through the third
throughhole of one shaft. Fluid is then supplied through the flow
passage built in one circular board to one end of the flow passage
built in the cylindrical section. And fluid is discharged to the
outside from the fourth throughhole of the other shaft through the
other end of the flow passage and the flow passage built in the
other circular board connected with the other end. In this way,
fluid circulates in the flow passage.
[0028] Outside diameter, inside diameter and length of the
cylindrical section, the cross-sectional shape, size of the cross
section and intervals of the flow passage built in the cylindrical
section, etc. are appropriately selected according to purpose of
use of the film formation roller etc.
[0029] When a film is formed on a film, more generally, a body to
be film-formed by a roll-to-roll method in the sputtering device
using the film formation roller described above, it is possible to
carry the body to be film-formed smoothly while the surface of the
body to be film-formed is kept flat and control temperature of the
body to be film-formed promptly and accurately, thereby performing
good film formation.
[0030] Preferably, the film formation roller around which the body
to be film-formed on which film formation is performed by a
roll-to-roll method is wound, having the cylindrical section made
of copper, copper alloy, aluminum and aluminum alloy having the
built-in flow passage at least in the effective section of the film
formation roller can be easily made by following two making
methods.
[0031] A first method for making a film formation roller,
comprising steps of:
[0032] using a first flat board having the same rectangular or
square planar shape as a planar shape obtained by expanding the
cylindrical section in a plane, a groove comprising a lower groove
having the same planar shape as the flow passage obtained by
expanding the cylindrical section in a plane and an upper groove
larger than the lower groove, having a planar shape almost similar
to the lower groove being provided on one major surface of the
first flat board and putting a second flat board in the upper
groove of the groove of the first flat board,
[0033] joining a boundary section of the first flat board and the
second flat board by friction stir welding; and
[0034] rounding a flat board having a rectangular or square planar
shape, which is formed by the first flat board and the second flat
board, the boundary section of the first flat board and the second
flat board being joined by friction stir welding, in a direction
parallel to one side of the flat board and joining one end and the
other end of the rounded board.
[0035] A second method for making the film formation roller
comprises steps of:
[0036] rounding a flat board having the same rectangular or square
planar shape as a planar shape obtained by expanding the
cylindrical section in a plane in a direction parallel to one side
of the flat board like a cylinder and joining one end and the other
end of the rounded board; and
[0037] forming the flow passage by forming throughholes extending
from one end to the other end of the rounded board at a plurality
of places in equal intervals in the circumferential direction of
the rounded board parallel to the central axis of the rounded
board.
[0038] The first flat board and the second flat board are made of
material as the same as material forming the cylindrical section,
which is copper, copper alloy, aluminum or aluminum alloy. In these
methods for making the film formation roller, other than the above,
the explanation mentioned above in connection with the film
formation roller comes into effect unless it is contrary to its
character.
Effect of the Invention
[0039] According to the invention, since the sputtering target of
the sputtering cathode has a tubular shape having the
cross-sectional shape having a pair of long side sections facing
each other, that is, a shape surrounded in all directions and an
erosion surface faces inward, when the sputtering cathode is
attached to a sputtering device and discharge is performed, it is
possible to generate a plasma circulating along the inner surface
of the sputtering target on the side of the erosion surface of the
sputtering target. Therefore, it is possible to increase plasma
density and obtain sufficiently high deposition rate. Furthermore,
the place where much plasma is generated is limited to the vicinity
of the surface of the sputtering target, it is possible to lower
risk of causing damage of the body to be film-formed from
irradiation of light emitted from the plasma to a minimum.
[0040] Furthermore, especially in a sputtering device in which film
formation is performed by a roll-to-roll method, by using the film
formation roller having the cylindrical section made of copper,
copper alloy, aluminum or aluminum alloy having the built-in flow
passage at least in the effective section of the film formation
roller as the film formation roller around which the body to be
film-formed on which film formation is performed is wound, it is
possible not only to cool or heat the cylindrical section promptly
and effectively by pouring, for example, cooling water or hot water
into the flow passage built in the cylindrical section because
copper, copper alloy, aluminum and aluminum alloy has high thermal
conductivity but also to avoid the problem that the film formation
roller is deformed like a beer barrel in vacuum such as the
conventional film formation roller described above. Therefore, when
a film is formed on the body to be film-formed by a roll-to-roll
method in the sputtering device, it is possible to carry the film
smoothly while the surface of the body to be film-formed is kept
flat. In addition, since the cylindrical section made of copper,
copper alloy, aluminum or aluminum alloy having high thermal
conductivity responds to heat quickly, it is possible to control
temperature of the cylindrical section promptly and accurately by
temperature, flow rate, etc. of, for example, cooling water or hot
water poured into the flow passage and finally control temperature
of the body to be film-formed wound around the cylindrical section
promptly and accurately.
BRIEF DESCRIPTION OF THE DRAWINGS
[0041] [FIG. 1] A longitudinal cross-sectional view showing a
sputtering device according to a first embodiment of the
invention.
[0042] [FIG. 2] A plan view showing a sputtering cathode of the
sputtering device according to the first embodiment of the
invention.
[0043] [FIG. 3] A longitudinal cross-sectional view showing a state
where a plasma is generated near the surface of the sputtering
target in the sputtering device according to the first embodiment
of the invention.
[0044] [FIG. 4] A plan view showing a state where the plasma is
generated near the surface of the sputtering target in the
sputtering device according to the first embodiment of the
invention.
[0045] [FIG. 5] A longitudinal cross-sectional view showing a
method for forming a thin film on a substrate by the sputtering
device according to the first embodiment of the invention.
[0046] [FIG. 6] A longitudinal cross-sectional view showing the
method for forming a thin film on the substrate by the sputtering
device according to the first embodiment of the invention.
[0047] [FIG. 7] A longitudinal cross-sectional view showing the
method for forming a thin film on the substrate by the sputtering
device according to the first embodiment of the invention.
[0048] [FIG. 8] A longitudinal cross-sectional view showing the
method for forming a thin film on the substrate by the sputtering
device according to the first embodiment of the invention.
[0049] [FIG. 9] A plan view showing the structure of the sputtering
cathode and the anode as an example of the sputtering device
according to the first embodiment of the invention.
[0050] [FIG. 10] A plan view showing a sputtering device according
to a third embodiment of the invention.
[0051] [FIG. 11] A longitudinal cross-sectional view showing a
method for forming a thin film on a substrate by the sputtering
device according to the third embodiment of the invention.
[0052] [FIG. 12] A longitudinal cross-sectional view showing the
method for forming a thin film on the substrate by the sputtering
device according to the third embodiment of the invention.
[0053] [FIG. 13] A longitudinal cross-sectional view showing the
method for forming a thin film on the substrate by the sputtering
device according to the third embodiment of the invention.
[0054] [FIG. 14] A longitudinal cross-sectional view showing the
method for forming a thin film on the substrate by the sputtering
device according to the third embodiment of the invention.
[0055] [FIG. 15] A longitudinal cross-sectional view showing a
sputtering device according to a fourth embodiment of the
invention.
[0056] [FIG. 16] A plan view showing a sputtering cathode of a
sputtering device according to a fifth embodiment of the
invention.
[0057] [FIG. 17A] A front view showing a film formation roller used
in a sputtering device according to a sixth embodiment of the
invention.
[0058] [FIG. 17B] A left side view showing the film formation
roller used in the sputtering device according to the sixth
embodiment of the invention.
[0059] [FIG. 17C] A right side view showing the film formation
roller used in the sputtering device according to the sixth
embodiment of the invention.
[0060] [FIG. 17D] A longitudinal cross-sectional view showing the
film formation roller used in the sputtering device according to
the sixth embodiment of the invention.
[0061] [FIG. 18A] A plan view showing a state where a cylindrical
section of the film formation roller used in the sputtering device
according to the sixth embodiment of the invention is expanded in a
plane.
[0062] [FIG. 18B] A cross-sectional view along the B-B line of FIG.
18A.
[0063] [FIG. 19A] A plan view for explaining a method for making
the film formation roller used in the sputtering device according
to the sixth embodiment of the invention.
[0064] [FIG. 19B] A cross-sectional view along the B-B line of FIG.
19A.
[0065] [FIG. 20A] A plan view for explaining the method for making
the film formation roller used in the sputtering device according
to the sixth embodiment of the invention.
[0066] [FIG. 20B] A cross-sectional view along the B-B line of FIG.
20A.
[0067] [FIG. 21A] A plan view for explaining the method for making
the film formation roller used in the sputtering device according
to the sixth embodiment of the invention.
[0068] [FIG. 21B] A cross-sectional view along the B-B line of FIG.
21A.
[0069] [FIG. 22] A schematic view showing the sputtering device
according to the sixth embodiment of the invention.
[0070] [FIG. 23] A schematic view showing the sputtering device
according to the sixth embodiment of the invention.
MODES FOR CARRYING OUT THE INVENTION
[0071] Modes for carrying out the invention (hereinafter referred
as "embodiments") will now be explained below.
The First Embodiment
Sputtering Device
[0072] FIG. 1 and FIG. 2 are a longitudinal cross-sectional view
and a plan view showing the sputtering device according to the
first embodiment and show construction around a sputtering cathode
and an anode disposed inside a vacuum chamber of the sputtering
device. FIG. 1 is a cross-sectional view along the line 1-1 of FIG.
2.
[0073] As shown in FIG. 1 and FIG. 2, the sputtering device
comprises a sputtering target 10 having a rectangular tubular shape
in which the cross-sectional shape thereof is a rectangular, and an
erosion surface faces inward, a permanent magnet 20 disposed
outside the sputtering target 10 and a yoke 30 disposed outside the
permanent magnet 20. The sputtering target 10, the permanent magnet
20 and the yoke 30 form the sputtering cathode. The sputtering
cathode is generally fixed to the vacuum chamber in an electrically
isolated state. The permanent magnet 20 and the yoke 30 form a
magnet circuit. Although polarity of the permanent magnet 20 is as
shown in FIG. 1, opposite polarity may be used. A backing plate for
cooling is preferably disposed between the sputtering target 10 and
the permanent magnet 20, and for example cooling water is poured
into a flow passage formed inside the backing plate. An anode 40
having an L-shaped cross-sectional shape is disposed near the lower
end of a rectangular parallelepiped space surrounded by the
sputtering target 10 such that the erosion surface of the
sputtering target 10 is exposed. The anode 40 is generally
connected with the vacuum chamber put to earth. A light stopping
shield 50 having an L-shape cross-sectional shape is disposed near
the upper end of the rectangular parallelpiped space surrounded by
the sputtering target 10 such that the erosion surface of the
sputtering target 10 is exposed. The light stopping shield 50 is
made of electric conductor, typically metal. The light stopping
shield 50 serves also as the anode and is generally connected with
the vacuum chamber put to earth as the same as the anode 40.
[0074] As shown in FIG. 2, when the distance between the pair of
long side sections facing each other of the sputtering target 10 is
denoted as a and the distance between the pair of short side
sections facing each other of the sputtering target 10 is denoted
as b, b/a is selected to be not less than 2, generally not larger
than 40. a is generally selected to be not less than 50 mm and not
larger than 150 mm.
[0075] In the sputtering device, film formation is performed for a
substrate A (a body to be film-formed) held by a prescribed
carrying mechanism not illustrated above the space surrounded by
the sputtering target 10. Film formation is performed while the
substrate S is moved for the sputtering target 10 at a constant
speed in the direction traversing the long side sections of the
sputtering target 10. In FIG. 1, shown is as an example a case
where the substrate S is moved at a constant speed parallel to the
upper end surface of the sputtering target 10 in the direction
perpendicular to the long side sections of the sputtering target
10. Width of a film formation region of the substrate S in the
direction parallel to the long side sections of the sputtering
target 10 is selected to be less than b, and therefore the
substrate S is held between the pair of short side sections facing
each other of the sputtering target 10 when film formation is
performed. The width of the film formation region of the substrate
S is equal to the width of the substrate S when film formation is
performed on the whole surface of the substrate S. The substrate S
may be basically anything and is not particularly limited. The
substrate S may be a long film wound around a roller which is used
for a roll-to-roll process.
Method for Forming a Film by the Sputtering Device
[0076] After the vacuum chamber is evacuated to high vacuum by
vacuum pumps, an Ar gas is introduced into the space surrounded by
the sputtering target 10 as a sputtering gas. Thereafter, high
voltage, generally DC high voltage necessary to generate a plasm is
applied between the anode 40 and the sputtering cathode by a
prescribed power source. Generally, the anode 40 is put to earth
and negative high voltage (for example, -400V) is applied to the
sputtering cathode. With this, as shown in FIG. 3 and FIG. 4, a
plasma 60 circulating along the inner surface of the sputtering
target 10 is generated near the surface of the sputtering target
10.
[0077] Before film formation, the substrate S is located far from a
position above the space surrounded by the sputtering target
10.
[0078] The sputtering target 10 is sputtered by Ar ions in the
plasma 60 circulating along the inner surface of the sputtering
target 10. As a result, atoms constituting the sputtering target 10
are emitted upward from the space surrounded by the sputtering
target 10. In this case, although atoms are emitted from everywhere
near the plasma 60 of the erosion surface of the sputtering target
10, atoms emitted from the erosion surface of the short side
sections of the sputtering target 10 are not basically used for
film formation. A way to accomplish this is to prevent atoms
emitted from the erosion surface of the short side sections of the
sputtering target 10 from reaching the substrate S during film
formation by disposing a horizontal shield plate above the
sputtering target 10 so as to shield both ends of the sputtering
target 10 in the long side direction. Alternatively, it is possible
to prevent atoms emitted from the erosion surface of the short side
sections of the sputtering ratget 10 from reaching the substrate S
during film formation by setting the width b of the sputtering
target 10 in the longitudinal direction sufficiently larger than
the width of the substrate S. A part of the atoms emitted from the
sputtering target 10 is shielded by the light stopping shield 50.
As a result, beams of sputtered particles 70 and 80 shown in FIG. 5
are obtained from the erosion surface of the long side sections of
the sputtering target 10. The beams of sputtered particles 70 and
80 have a nearly uniform intensity distribution in the longitudinal
direction of the sputtering target 10.
[0079] When the stable beams of sputtered particles 70 and 80 are
obtained, film formation is performed by the beams of sputtered
particles 70 and 80 while the substrate S is moved for the
sputtering target 10 at a constant speed in the direction
traversing the long side sections of the sputtering target 10. When
the substrate S is moved toward a position above the space
surrounded by the sputtering target 10, the beam of sputtered
particles 70 first irradiates the substrate S to begin film
formation. FIG. 6 shows a state when the front of the substrate S
just reaches a position above the center of the space surrounded by
the sputtering target 10. At this time, the beam of sputtered
particles 80 does not contribute to film formation. When the
substrate S is moved further and the beam of sputtered particles 80
begins to irradiate the substrate S, the beam of sputtered
particles 80 begins to contribute film formation in addition to the
beam of sputtered particles 70. FIG. 7 shows a state when the
substrate S is moved to a position just above the space surrounded
by the sputtering target 10. As shown in FIG. 7, the beams of
sputtered particles 70 and 80 irradiate the substrate S to perform
film formation. The substrate S is moved further while film
formation is performed in this way. And as shown in FIG. 8, the
substrate S is moved to a place far from the position above the
space surrounded by the sputtering target 10 where the beams of
sputtered particles 70 and 80 do not irradiate the substrate S. In
this way, a thin film F is formed on the substrate S.
Example of the Sputtering Cathode and the Anode of the Sputtering
Device
[0080] As shown in FIG. 9, the sputtering target 10 is formed by
four boardlike sputtering targets 10a, 10b, 10c and 10d, the
permanent magnet 20 is formed by four boardlike or rodlike
permanent magnets 20a, 20b, 20c and 20d and the yoke 30 is formed
by four boardlike yokes 30a, 30b, 30c and 30d. Backing plates 90a,
90b, 90c and 90d are inserted between the sputtering targets 10a,
10b, 10c and 10d and the permanent magnets 20a, 20b, 20c and 20d,
respectively. The distance between the sputtering target 10a and
the sputtering target 10c is set to 80 mm, the distance between the
sputtering target 10b and the sputtering target 10d is set to 200
mm and the heights of the sputtering targets 10a, 10b, 10c and 10d
are set to 80 mm.
[0081] Four boardlike anodes 100a, 100b, 100c and 100d are formed
outside the yokes 30a, 30b, 30c and 30d. The anodes 100a, 100b,
100c and 100d are connected to the vacuum chamber put to earth
together with the anode 40.
[0082] As described above, according to the first embodiment, since
the sputtering cathode has the sputtering target 10 having a
rectangular tubular shape in which the cross-sectional shape
thereof is a rectangular, and the erosion surface thereof faces
inward, various advantages can be obtained as follows. That is, it
is possible to generate the plasma 60 circulating along the inner
surface of the sputtering target 10 on the side of the erosion
surface of the sputtering target 10. Therefore, it is possible to
increase the density of the plasma 60 to increase the rate of film
formation sufficiently. Furthermore, the place where plenty of the
plasma 60 is generated is limited near the surface of the
sputtering target 10. In addition to this, the light stopping
shield 50 is disposed. With this, it is possible to lower the risk
of causing damage to the substrate S by irradiation of light
generated from the plasma 60 to a minimum. Lines of magnetic force
generated by the magnetic circuit formed by the permanent magnet 20
and the yoke 30 are restricted to the sputtering cathode and not
bound for the substrate S. Therefore, there is no risk of causing
damage to the substrate S by the plasma 60 and an electron beam.
Since film formation is performed by using the beams of sputtered
particles 70 and 80 obtained from the long side sections facing
each other of the sputtering target 10, it is possible to lower the
risk of causing damage to the substrate S by bombardment of high
energy particles of reflected sputtering neutral gases.
Furthermore, the beams of sputtered particles 70 and 80 obtained
from the long side sections facing each other of the sputtering
target 10 have a uniform intensity distribution in the direction
parallel to the long side sections. In addition to this, film
formation is performed while the substrate S is moved at a constant
speed in the direction traversing the long side sections, for
example the direction perpendicular to the long side sections.
Therefore, it is possible to reduce unevenness of the thickness of
the thin film F formed on the substrate S. For example, thickness
distribution of the thin film F can be controlled within .+-.5%.
The sputtering device is preferably applied to film formation of
electrode materials in various devices such as semiconductor
devices, solar batteries, liquid crystal displays, organic EL
displays.
The Second Embodiment
Sputtering Device
[0083] In the sputtering device, the sputtering target 10 comprises
the sputtering targets 10a, 10b, 10c and 10d shown in FIG. 9. Here,
the sputtering targets 10a and 10b forming the long side sections
facing each other are made of materials different from each other.
Other construction of the sputtering device is as the same as the
sputtering device according to the first embodiment.
Method for Forming a Film by the Sputtering Device
[0084] As the same as the first embodiment, film formation is
performed in the film formation region of the substrate S by using
the beams of sputtered particles 70 and 80. In this case, since the
sputtering targets 10a and 10b are made of materials different from
each other, constituent atoms of the beam of sputtered particles 70
and constituent atoms of the beam of sputtered particles 80 are
different from each other. Therefore, the thin film F formed on the
substrate S has the composition in which constituent atoms of the
beam of sputtered particles 70 and constituent atoms of the beam of
sputtered particles 80 are mixed, in other words, almost the
composition in which constituent atoms of the material forming the
sputtering target 10a and constituent atoms of the material forming
the sputtering target 10c are mixed.
[0085] According to the second embodiment, it is possible to obtain
further advantage that it is possible to form the thin film F
having the composition in which the constituent atoms of the
material forming the sputtering target 10a and the constituent
atoms of the material forming the sputtering target 10c are mixed.
Therefore, for example, by forming the sputtering target 10a by
titanium having the function of improving adhesiveness of a thin
film and by forming the sputtering target 10c by another metal, it
is possible to form the thin film F having the composition in which
titanium and another metal are mixed to obtain the thin film F
having excellent cohesiveness for the substrate S.
The Third Embodiment
Sputtering Device
[0086] FIG. 10 shows the sputtering device according to the third
embodiment. In the sputtering device, as the same as the sputtering
device according to the second embodiment, the sputtering target 10
comprises the sputtering targets 10a, 10b, 10c and 10d shown in
FIG. 9, the sputtering targets 10a and 10c of the long side
sections facing each other being made of materials different from
each other. In addition, as shown in FIG. 10, in the sputtering
device, a horizontal shield plate 90 held by a carrying mechanism
not illustrated can be placed at a height between the height of the
substrate S and the height of the light stopping shield 50 so as to
stop the beam of sputtered particles 80 from the sputtering target
10c or the beam of sputtered particles 70 from the sputtering
target 10a. Other construction of the sputtering device is as the
same as the sputtering device according to the first
embodiment.
Method for Forming a Film by the Sputtering Device
[0087] For example, in order to form a thin film on the substrate S
by only the beam of sputtered particles 70, the horizontal shield
plate 90 is first moved to a position shown by an alternate long
and short dashes line in FIG. 10. At this moment, the beam of
sputtered particles 80 is stopped by the horizontal shield plate
90. In this state, film formation is performed in the film
formation region of the substrate S by using only the beam of
sputtered particles 70 as shown in FIG. 11 while the substrate S is
moved in the direction shown by an arrow in FIG. 10. As shown in
FIG. 12, the substrate S is moved to a position far from the
position above the space surrounded by the sputtering targets 10a,
10b, 10c and 10d. In this way, a thin film Fi is formed. The thin
film Fi is composed of constituent atoms of the beam of sputtered
particles 70, almost constituent atoms of the material forming the
sputtering target 10a. Next, the horizontal shield plate 90 is
moved to a position shown by an alternate long and two short dashes
line where the beam of sputtered particles 70 is stopped as shown
in FIG. 10. In this state, as shown in FIG. 13, film formation is
performed in the film formation region of the substrate S by using
only the beam of sputtered particles 80 while the substrate S is
moved in the direction opposite to the direction shown by the arrow
in FIG. 10. As shown in FIG. 14, the substrate S is moved to a
position far from the position above the space surrounded by the
sputtering targets 10a, 10b, 10c and 10d. In this way, a thin film
F.sub.2 is formed on the thin film F.sub.1. The thin film F.sub.2
is composed of constituent atoms of the beam of sputtered particles
80, almost constituent atoms of the material forming the sputtering
target 10c. Thus, it is possible to form the two-layer film made of
the thin film F.sub.1 and the thin film F.sub.2 having compositions
different from each other.
[0088] In order to prevent constituent atoms of the thin film
F.sub.1 from containing constituent atoms of the material forming
the sputtering target 10c and on the contrary in order to prevent
constituent atoms of the thin film F.sub.2 from containing
constituent atoms of the material forming the sputtering target
10a, for example, as shown in FIG. 10, a vertical shield plate 100
may be inserted into the central part of the space between the
sputtering target 10a and the sputtering target 10c to prevent
constituent atoms of the material forming the sputtering target 10c
from mixing with the beam of sputtered particles 70 and to prevent
constituent atoms of the material forming the sputtering target 10a
from mixing with the beam of sputtered particles 80. One of the
characteristics of the sputtering cathode is that the vertical
shield plate 100 can be inserted in this way. That is, in the
sputtering cathode, the plasma 60 circulates near the surface of
the four boardlike sputtering targets 10a, 10b, 10c and 10d and the
plasma 60 is not generated in the central part of the space between
the sputtering target 10a and the sputtering target 10c. A shield
plate inclined to the vertical direction may be used instead of the
vertical shield plate 100.
[0089] According to the third embodiment, in addition to the same
advantages as the first embodiment, it is possible to obtain
further advantage that it is possible to form the two-layer film
made of the thin film F.sub.1 and the thin film F.sub.2 having
compositions different from each other. Therefore, for example, by
forming the sputtering target 10a from titanium having the function
of improving adhesiveness of a thin film and forming the sputtering
target 10c from another metal, it is possible to form first the
thin film F.sub.1 composed of titanium having excellent
adhesiveness for the substrate S and then form the thin film
F.sub.2 composed of another metal thereon to obtain the two-layer
film made of the thin film F.sub.1 having excellent adhesiveness
for the substrate S and the thin film F.sub.2.
The Fourth Embodiment
Sputtering Device
[0090] The sputtering device according to the fourth embodiment has
basically the same structure as the sputtering device according to
the first embodiment. In the first embodiment, film formation is
performed by using the beams of sputtered particles 70 and 80 taken
out over the space surrounded by the sputtering target 10 while the
substrate S is moved. In the fourth embodiment, in addition to
this, as shown in FIG. 15, film formation is performed on another
substrate by using beams of sputtered particles 70' and 80' taken
out below the space surrounded by the sputtering target 10 from the
long side sections facing each other of the sputtering target 10.
Here, in the sputtering device, for example, by fixing the
sputtering cathode and the anode 40 to the inner surface of the
sidewall of the vacuum chamber, it is possible to secure space for
film formation below the space surrounded by the sputtering target
10.
Method for Forming a Film by the Sputtering Device
[0091] As shown in FIG. 15, the beams of sputtered particles 70 and
80 are taken above the space surrounded by the sputtering target 10
and at the same time the beams of sputtered particles 70' and 80'
are taken below the space surrounded by the sputtering target 10.
Film formation is performed on the substrate S by using the beams
of sputtered particles 70 and 80 above the space surrounded by the
sputtering target 10 while the substrate S is moved for the
sputtering target 10 in the direction traversing the long side
sections of the sputtering target 10. At the same time, film
formation is performed on the substrate S' by using the beams of
sputtered particles 70' abd 80' below the space surrounded by the
sputtering target 10 while the substrate S' is moved for the
sputtering target 10 in the direction traversing the long side
sections of the sputtering target 10. That is, it is possible to
perform film formation on the substrate S above the space
surrounded by the sputtering target 10 and perform at the same time
film formation on the substrate S' below the space surrounded by
the sputtering target 10.
[0092] According to the fourth embodiment, in addition to the same
advantages as the first embodiment, it is possible to obtain
further advantage that it is possible to increase productivity
markedly because film formation can be performed on the two
substrates S and S' at the same time.
The Fifth Embodiment
Sputtering Device
[0093] The sputtering device according to the fifth embodiment
differs from the sputtering device according to the first
embodiment in that the sputtering target 10 shown in FIG. 16 is
used. That is, as shown in FIG. 16, the sputtering target 10
comprises a pair of long side sections facing parallel each other
and semicircular sections connected to the long side sections. The
permanent magnet 20 disposed outside the sputtering target 10 and
the yoke 30 disposed outside the permanent magnet 20 have the same
shape as the sputtering target 10. Other construction of the
sputtering device is the same as the sputtering device according to
the first embodiment.
Method for Forming a Film by the Sputtering Device
[0094] The method for forming a film by the sputtering device is
the same as the first embodiment.
[0095] According to the fifth embodiment, it is possible to obtain
the same advantages as the first embodiment.
The Sixth Embodiment
Sputtering Device
[0096] The sputtering device according to the sixth embodiment is a
sputtering device in which film formation is performed by a
roll-to-roll method and differs from the sputtering device
according to the first embodiment in that the film formation roller
shown in FIG. 17A, FIG. 17B, FIG. 17C and FIG. 17D is used as the
film formation roller around which a body to be film-formed is
wound. Here, FIG. 17A is a front view, FIG. 17B is a left side
view, FIG. 17C is a right side view and FIG. 17D is a longitudinal
cross-sectional view.
[0097] As shown in FIG. 17A, FIG. 17B, FIG. 17C and FIG. 17D, the
film formation roller comprises a cylindrical section 210, circular
boards 220 and 230 attached to both ends of the cylindrical section
210 such as to close the cylindrical section 210, and a shaft 240
disposed on the central axis of the film formation roller,
therefore the cylindrical section 210 outside the circular boards
220 and 230.
[0098] The cylindrical section 210 has a built-in flow passage 211
having the rectangular cross-sectional shape parallel to the
central axis of the cylindrical section 210. That is, the flow
passage 211 is buried in the cylindrical section 210. FIG. 18A is a
plan view in a state in which the cylindrical section 210 is
expanded in a plane and FIG. 18B is a cross-sectional view along
the B-B line of FIG. 18A. As shown in FIG. 18A and FIG. 18B, in the
example, the shape when the cylindrical section 210 is expanded in
a plane is a rectangular and the flow passage 211 has a linear
section 211a elongating parallel to long sides of the rectangle and
a turn back section 211b folded vertical to the linear section
211a, which are provided alternately, and has a zigzag folded
shape. A hole 212 serving as an inlet of fluid such as cooling
water is formed on one end of the flow passage 211 and a hole 213
serving as an outlet of fluid is formed on the other end thereof.
The cylindrical section 210 is made of copper, copper alloy,
aluminum or aluminum alloy, preferably made of oxygen free copper
having the highest thermal conductivity among these materials.
Thermal conductivity of oxygen free copper is about twenty three
times higher than that of stainless steel (SUS304), for example.
Although not illustrated, hard chromium plating is formed on at
least the outer peripheral surface, typically the outer peripheral
surface and the inner peripheral surface of the cylindrical section
210. If the hard chromium plating layer is too thick, thermal
conductivity of the cylindrical section 210 decreases. If the hard
chromium plating layer is too thin, effect of surface hardening of
the cylindrical section 210 is little. Therefore, the thickness of
the hard chromium plating layer is generally selected to be not
less than 20 .mu.m and not larger than 40 .mu.m, for example 30
.mu.m. Hardness of the hard chromium plating layer may be, for
example, not less than 500 in Vickers hardness. If necessary, the
surface of the hard chromium plating layer is flattened by
polishing to decrease surface roughness R.sub.a drastically, for
example, to about 10 nm.
[0099] The circular boards 220 and 230 are fixed to both ends of
the cylindrical section 210 by bolting, welding, etc. Four circular
throughholes 221 to 224 are formed in the circular board 220 every
90.degree. around the central axis. Similarly, four circular
throughholes 231 to 234 are formed in the circular board 230 every
90.degree. around the central axis at positions corresponding to
the throughholes 221 to 224 of the circular board 220. The
throughholes 221 to 224 and 231 to 234 are formed so that when the
film formation roller is installed in the vacuum chamber of the
sputtering device and the vacuum chamber is evacuated, pressure
difference between the inside and the outside of the cylindrical
section 210 is eliminated to prevent external force resulting from
the pressure difference from applying to the cylindrical section
210 and the circular boards 220 and 230. Diameters of the
throughholes 221 to 224 and 231 to 234 are appropriately selected
so as to obtain mechanical strength of the circular boards 220 and
230. The circular boards 220 and 230 are made of, for example,
stainless steel.
[0100] A throughhole 241 having the circular cross-sectional shape
is formed on the central axis of the shaft 240 fixed to the
circular board 220. The throughhole 241 comprises a section 241a
having the diameter d.sub.1 extending from the front end of the
shaft 240 to an intermediate depth position and a section 241b
having the diameter d.sub.2 smaller than d.sub.1 extending from the
intermediate depth position to the circular board 220. A
throughhole 225 communicating with the section 241b is formed in
the circular board 220 on the central axis of the shaft 240. One
end of a pipe 251 is hermetically fixed such as to communicate with
the throughhole 225. The other end of the pipe 251 is connected
with the hole 212 formed on the end of the flow passage 211 on the
side of the circular board 220. Similarly, a throughhole 242 having
the circular cross-sectional shape is formed on the central axis of
the shaft 240 fixed to the circular board 230. The throughhole 242
comprises a section 242a having the diameter d.sub.1 extending from
the front end of the shaft 240 to an intermediate depth position
and a section 242b having the diameter d.sub.2 smaller than d.sub.1
extending from the intermediate depth position to the circular
board 230. A throughhole 235 communicating with the section 242b is
formed in the circular board 230 on the central axis of the shaft
240. One end of a pipe 252 is hermetically fixed such as to
communicate with the throughhole 235. The other end of the pipe 252
is connected with the hole 213 formed on the end of the flow
passage 211 on the side of the circular board 230. A flexible metal
pipe, for example, a bellows pipe is preferably used as the pipes
250 and 251. Fluid is supplied from, for example, the throughhole
241 of the shaft 240 fixed to the circular board 220 by a fluid
circulation mechanism not illustrated, poured into the flow passage
211 from the hole 212 of the cylindrical section 210 through the
pipe 251, ejected from the hole 231 through the flow passage 211,
ejected from the throughhole 242 of the shaft 240 fixed to the
circular board 230 through the pipe 252 and circulated in the
path.
[0101] Size of each section of the film formation roller is
appropriately selected. Sizes are exemplified as the total length
of 500 mm, diameter of 400 mm, thickness of the cylindrical section
210 of 10 mm, cross section of the flow passage 211 of 35
mm.times.5 mm and interval of the flow passage 211 of 15 mm.
[0102] The film formation roller can be made as follows, for
example.
[0103] As shown in FIG. 19A and FIG. 19B, prepared is a rectangular
flat board 260 having the same planar shape as the one shown in the
expansion plan of the cylindrical section 210 shown in FIG. 18A and
FIG. 18B. Here, FIG. 19A is a plan view and FIG. 19B is a
cross-sectional view along the B-B line in FIG. 19A. The thickness
of the flat board 260 is the same as the thickness of the
cylindrical section 210. A groove 26 having the cross-sectional
shape with a step is formed on one major plane of the flat board
260. A lower groove 261a of the groove 261 has the same planar
shape and depth as the flow passage 211 when the cylindrical
section 210 is expanded in a plane. An upper groove 261b of the
groove 261 has a planar shape which is similar to the lower groove
261 and a size larger. The flat board 260 has a hole 212 formed in
the bottom of one end of the lower groove 261a of the groove 261
and a hole 213 formed in the bottom of the other end of the lower
groove 261a of the groove 261.
[0104] Next, as shown in FIG. 20A and FIG. 20B, prepared is a flat
board 270 having the same planar shape as the upper groove 261b of
the groove 261 of the flat board 260 and the thickness as the same
as the depth of the upper groove 261b. Here, FIG. 20A is a plan
view and FIG. 20B is a cross-sectional view along the B-B line of
FIG. 20A.
[0105] Next, as shown in FIG. 21A and FIG. 21B, the flat board 270
is fitted to the upper groove 261b of the groove 261 of the flat
board 260. Here, FIG. 21A is a plan view and FIG. 21B is a
cross-sectional view along the B-B line of FIG. 21A.
[0106] Next, the boundary section (the linear section and the turn
back section) between the flat board 260 and the flat board 270
shown in FIG. 21A and FIG. 21B is joined by friction stir welding.
In this way, obtained is a rectangular flat board 280 in which the
lower groove 261a of the groove 261 serving as the flow passage 211
is formed between the flat board 260 and the flat board 270.
[0107] Next, the flat board 280 is rounded in its longitudinal
direction such that the surface of the flat board 280 on which
friction stir welding was performed faces outward, one short side
and the other short side of the board rounded like a cylinder are
made contact with each other and jointed by friction stir welding.
In this way, made is the cylindrical section 210 having the
built-in flow passage 211 formed by the lower groove 261a of the
groove 261 of the flat board 260.
[0108] Thereafter, the circular boards 220 and 230 and the shaft
240 are fixed to both ends of the cylindrical section 210.
[0109] As described above, the target film formation roller shown
in FIG. 17A, FIG. 17B, FIG. 17C and FIG. 17D is made.
[0110] FIG. 22 and FIG. 23 show the sputtering device according to
the sixth embodiment using the film formation roller shown in FIG.
17A, FIG. 17B, FIG. 17C and FIG. 17D. Here, FIG. 22 is a schematic
view of the inside of the vacuum chamber of the sputtering device
seen from a direction parallel to the film formation roller and
FIG. 23 is a schematic view of the inside of the vacuum chamber of
the sputtering device seen from a direction perpendicular to the
film formation roller.
[0111] As shown in FIG. 22 and FIG. 23, in the sputtering device,
the inside of the vacuum chamber 290 is vertically partioned into
two sections by a partion board 291. A lower space below the
partion board 291 of the inside of the vacuum chamber 290 is a film
formation room C.sub.1 and an upper space above the partion board
291 thereof is a film carrying room C.sub.2. The film formation
roller shown in FIG. 17A, FIG. 17B, FIG. 17C and FIG. 17D is
disposed horizontally inside the film formation room C.sub.1 as a
film formation roller R.sub.1. Both ends of the shaft 240 on both
ends of the cylindrical section 210 of the film formation roller
R.sub.1 are inserted into a circular hole formed in support boards
292 and 293 fixed to both sidewalls of the film formation room
C.sub.1 and a circular hole formed in the both sidewalls of the
film formation room C.sub.1 and are rotatably supported by these
holes. For example, three sputtering cathodes K.sub.1, K.sub.2 and
K.sub.3 are disposed on the inner wall of the film formation room
C.sub.1. Among them, the sputtering cathode K.sub.1 is disposed on
the bottom of the film formation room C.sub.1 through an insulating
member 294 and electrically isolated from the vacuum chamber 290.
The sputtering cathodes K.sub.2 and K.sub.3 are disposed on
sidewalls facing each other of the film formation room C.sub.1
through the insulating member 294, respectively. The sputtering
cathodes K.sub.1, K.sub.2 and K.sub.3 may have the similar
structure or different structures, but at least the sputtering
cathode K.sub.1 has the same structure as the first embodiment. A
shield plate 295 is disposed around the cylindrical section 210 of
the film formation roller R.sub.1 to limit beams of sputtered
particles generated from the sputtering cathodes K.sub.1, K.sub.2
and K.sub.3 and irradiated a film when film formation is performed
on a film. On the other hand, rollers R.sub.2 and R.sub.3 for
unwinding/winding and carrying rollers (or guide rollers) R.sub.4,
R.sub.5, R.sub.6 and R.sub.7 are disposed in the film carrying room
C.sub.2. Axes of the rollers R.sub.2 and R.sub.3 for
unwinding/winding (only an axis S.sub.3 of the roller R.sub.3 is
illustrated in FIG. 23) are inserted into a circular hole formed in
the support boards 292 and 293 fixed to both sidewalls of the film
formation room C.sub.1 and a circular hole formed in the both
sidewalls of the film formation room C.sub.1 and are rotatably
supported by these holes. Axes of the carrying rollers R.sub.4,
R.sub.5, R.sub.6 and R.sub.7 (only axes S.sub.6 and S.sub.7 of the
carrying rollers R.sub.6 and R.sub.7 are illustrated in FIG. 23)
are rotatably supported by circular holes formed in the support
boards 292 and 293. A film 300 is carried by the roller R.sub.2 for
unwinding/winding, the carrying rollers R.sub.4 and R.sub.5, the
film formation roller R.sub.1, the carrying rollers R.sub.6 and
R.sub.7 and the roller R.sub.3 for unwinding/winding. The film 300
can be carried by rotating the rollers R.sub.2 and R.sub.3 by a
rotation mechanism not illustrated which is fixed to the shafts
S.sub.2 and S.sub.3 of the rollers R.sub.2 and R.sub.3. In this
case, by rotating the rollers R.sub.2 and R.sub.3 counterclockwise
in FIG. 22, the film 300 can be unwinded from the roller R.sub.2,
carried through the carrying rollers R.sub.4 and R.sub.5, the film
formation roller R.sub.1 and the carrying rollers R.sub.6 and
R.sub.7 and wound by the roller R.sub.3. In contrast to this, by
rotating the rollers R.sub.2 and R.sub.3 clockwise in FIG. 22, the
film 300 can be unwound from the roller R.sub.3, carried through
the carrying rollers R.sub.7 and R.sub.6, the film formation roller
R.sub.1 and the carrying rollers R.sub.5 and R.sub.4 and wound by
the roller R.sub.2. That is, the film 300 can be carried in
opposite directions. With this, for example, film formation is
performed on the film formation roller R.sub.1 while the film 300
is carried by rotating the rollers R.sub.2 and R.sub.3
counterclockwise in FIG. 22, and thereafter film formation is
performed on the film formation roller R.sub.1 while the film 300
is carried reversely by rotating the rollers R.sub.2 and R.sub.3
clockwise in FIG. 22. By repeating such film formation several
times, a multi-layer thin film can be formed on the film 300. If
necessary, at least one of the carrying rollers R.sub.4 to R.sub.7
may be constituted as the same as the film formation roller R.sub.1
and used as a cooling roller. With this, the film 300 heated during
film formation on the film formation roller R.sub.1 can be cooled
by the cooling roller while the film 300 is carried before the film
300 is wound by the roller R.sub.2 or the roller R.sub.3.
Therefore, it is possible to prevent the problem of abrasion formed
by mutual rubbing of the film 300 when the film 300 is cooled to
shrink after the film 300 is wound by the roller R.sub.2 or the
roller R.sub.3 at a high temperature. Slitlike holes 291a and 291b
are formed in the partion board 291 to pass the film 300.
[0112] In the sputtering device, film formation is performed above
the space surrounded by the sputtering target 10 while the film 300
wound around the cylindrical section 210 of the film formation
roller R.sub.1 is carried. In this case, the film 300 is carried
for the sputtering target 10 in the direction traversing the long
side sections of the sputtering target 10. The width of the film
formation region of the film 300 in the direction parallel to the
long side sections of the sputtering target 10 is selected to be
less than b, and therefore the film 300 is held between the pair of
short side sections facing each other of the sputtering target 10.
The width of the film formation region is equal to the width of the
film 300 when film formation is performed on the whole surface of
the film 300.
Method for Forming a Film by the Sputtering Device
[0113] Although it is possible to perform film formation using two
or more of the sputtering cathodes K.sub.1, K.sub.2 and K.sub.3,
described here is a case where film formation is performed by using
only the sputtering cathode K.sub.1.
[0114] Water is circulated through the flow passage 211 of the
cylindrical section 210 of the film formation roller R.sub.1 and
temperature of the cylindrical section 210 is set to a temperature
at which film formation is performed on the film 300. If necessary,
an antifreeze solution such as ethylene glycol etc. is added to
water circulated in the flow passage 211. An example of a control
range of temperature of water circulated in the flow passage 211 is
-10.degree. C..about.80.degree. C.
[0115] The vacuum chamber 290 is evacuated to high vacuum by vacuum
pumps, thereafter an Ar gas is introduced into the space surrounded
by the sputtering target 10 as a sputtering gas and generally DC
high voltage necessary to generate plasma is applied between the
anode 40 and the sputtering cathode K.sub.1 by a prescribed power
source. Generally, the anode 40 is put to earth and negative high
voltage (for example, -400V) is applied to the sputtering cathode
K.sub.1. With this, as shown in FIG. 3 and FIG. 4, the plasma 60
circulating along the inner surface of the sputtering target 10 is
generated near the surface of the sputtering target 10.
[0116] The sputtering target 10 is sputtered by Ar ions in the
plasma 60 circulating along the inner surface of the sputtering
target 10. As a result, atoms constituting the sputtering target 10
are emitted upward from the space surrounded by the sputtering
target 10. In this case, although atoms are emitted from everywhere
near the plasma 60 of the erosion surface of the sputtering target
10, atoms emitted from the erosion surface of the short side
sections of the sputtering target 10 are not basically used for
film formation. To accomplish this, a horizontal shield plate may
be disposed above the sputtering target 10 so as to shield both
ends in the long side direction of the sputtering target 10, so
that it is possible to prevent atoms emitted from the erosion
surface of the short side sections of the sputtering target 10 from
reaching the film 300 during film formation. Alternatively, the
width b in the longitudinal direction of the sputtering target 10
may be set to be much larger than the width of the film 300, so
that it is possible to prevent atoms emitted from the erosion
surface of the short side sections of the sputtering target 10 from
reaching the film 300 during film formation. A part of atoms
emitted from the sputtering target 10 is stopped by the light
stopping shield 50. As a result, the beams of sputtered particles
70 and 80 shown in FIG. 5 are obtained from the erosion surface of
the long side sections of the sputtering target 10. The beams of
sputtered particles 70 and 80 have almost uniform intensity
distribution in the longituducal direction of the sputtering target
10.
[0117] When the stable beams of sputtered particles 70 and 80 are
obtained, the rollers R.sub.2 and R.sub.3 for unwinding/winding the
film 300 are rotated, for example, counterclockwise in FIG. 22, and
film formation is performed on the film 300 wound around the film
formation roller R.sub.1 from below by the beams of sputtered
particles 70 and 80 while the film 300 is carried at a constant
speed through the carrying rollers R.sub.4 and R.sub.5, the film
formation roller R.sub.1 and the carrying rollers R.sub.6 and
R.sub.7. In this case, tensional forces applied to the film 300 are
controlled to be a constant value about 10.about.100 Newton (N),
for example.
[0118] According to the sixth embodiment, since the cylindrical
section 210 of the film formation roller R.sub.1 is made of copper,
copper alloy, aluminum or aluminum alloy having excellent thermal
conductivity, it is possible to cool or heat promptly and
efficiently the cylindrical section 210 around which the film 300
to be film-formed is wound by pouring fluid such as cooling water
or warm water into the flow passage 211 built in the cylindrical
section 210, and furthermore it is possible to avoid the problem of
the conventional film formation roller described above that it is
deformed like a beer barrel in vacuum. Therefore, when film
formation is performed on the film 300 by a roll-to-roll method in
the sputtering device, it is possible to carry the film 300
smoothly, keeping the surface of the film 300 flat. In addition,
since thermal response of the cylindrical section 210 made of
copper, copper alloy, aluminum or aluminum alloy having excellent
thermal conductivity is good, it is possible to control temperature
of the cylindrical section 210 promptly and accurately by
temperature or flow rate of the fluid such as cooling water or warm
water poured into the flow passage 211, and therefore it is
possible to control temperature of the film 300 wound around the
cylindrical section 210 promptly and accurately, resulting good
film formation on the film 300.
[0119] Heretofore, embodiments and examples of the present
invention have been explained specifically. However, the present
invention is not limited to these embodiments and examples, but
contemplates various changes and modifications based on the
technical idea of the present invention.
[0120] For example, numerical numbers, materials, structures,
shapes, etc. presented in the aforementioned embodiments and
examples are only examples, and the different numerical numbers,
materials, structures, shapes, etc. may be used as necessary.
EXPLANATION OF REFERENCE NUMERALS
[0121] 10, 10a, 10b, 10c, 10d Sputtering target [0122] 20, 20a,
20b, 20c, 20d Permanent magnet [0123] 30, 30a, 30b, 30c, 30d Yoke
[0124] 40 Anode [0125] 50 Light stopping shield [0126] 60 Plasma
[0127] 70, 70', 80, 80' Beam of sputtered particles [0128] 90
Horizontal shield plate [0129] 100 Vertical shield plate [0130] S,
S' Substrate [0131] 210 Cylindrical section [0132] 211 Flow passage
[0133] 211a Linear section [0134] 211b Turn back section [0135]
220, 230 Circular board [0136] 240 Shaft [0137] 300 Film
* * * * *