U.S. patent application number 10/773245 was filed with the patent office on 2005-05-19 for plasma processing apparatus, ring member and plasma processing method.
This patent application is currently assigned to TOKYO ELECTRON LIMITED. Invention is credited to Moriya, Tsuyoshi, Nagaike, Hiroshi, Sasaki, Yasuharu.
Application Number | 20050103275 10/773245 |
Document ID | / |
Family ID | 34315569 |
Filed Date | 2005-05-19 |
United States Patent
Application |
20050103275 |
Kind Code |
A1 |
Sasaki, Yasuharu ; et
al. |
May 19, 2005 |
Plasma processing apparatus, ring member and plasma processing
method
Abstract
[Problem to be solved] In a plasma processing apparatus for
executing a process using plasma, promoting the sharing of an
apparatus in executing a plurality of different processes and
plasma states amongst apparatuses in executing same processes in a
plurality of apparatuses are provided. [Solution] A ring member
formed of an insulating material is disposed to surround a
to-be-treated substrate in a processing vessel and an electrode is
installed in the ring member for adjusting a plasma sheath region.
For example, a first DC voltage is applied to the electrode when a
first process is performed on the to-be-treated substrate and a
second DC voltage is applied to the electrode when a second process
is performed on the to-be-treated substrate. In this case, the
plasma state can be matched by applying an appropriate DC voltage
according to each process or each apparatus executing the same
process. Therefore, the sharing of an apparatus can be promoted and
the plasma state can be readily adjusted.
Inventors: |
Sasaki, Yasuharu;
(Nirasaki-shi, JP) ; Moriya, Tsuyoshi;
(Nirasaki-shi, JP) ; Nagaike, Hiroshi;
(Nirasaki-shi, JP) |
Correspondence
Address: |
OBLON, SPIVAK, MCCLELLAND, MAIER & NEUSTADT, P.C.
1940 DUKE STREET
ALEXANDRIA
VA
22314
US
|
Assignee: |
TOKYO ELECTRON LIMITED
Minato-ku
JP
|
Family ID: |
34315569 |
Appl. No.: |
10/773245 |
Filed: |
February 9, 2004 |
Current U.S.
Class: |
118/728 |
Current CPC
Class: |
H01J 37/32642 20130101;
H01J 37/32706 20130101; H01L 21/67069 20130101 |
Class at
Publication: |
118/728 |
International
Class: |
C23C 016/00 |
Foreign Application Data
Date |
Code |
Application Number |
Feb 7, 2003 |
JP |
2003-031278 |
Nov 28, 2003 |
JP |
2003-398334 |
Claims
What is claimed is:
1. A plasma processing apparatus for performing a processing on a
to-be-treated substrate mounted on a mounting table in a processing
vessel by plasma of a processing gas, comprising: a ring member
formed of an insulating material and installed to surround the
to-be-treated substrate on the mounting table; one or more
electrodes installed in the ring member; and a DC power supply for
applying a DC voltage to the one or more electrodes to adjust a
plasma sheath region above the ring member.
2. The plasma processing apparatus of claim 1, further comprising a
means for varying the applied voltage such that a first DC voltage
is applied to the one or more electrodes when a first process is
performed on the to-be-treated substrate and a second DC voltage is
applied to the one or more electrodes when a second process is
performed on the to-be-treated substrate.
3. The plasma processing apparatus of claim 2, wherein the first
process is etching of a thin film and the second process is etching
of another thin film which is different from the thin film in the
first process.
4. The plasma processing apparatus of claim 1, wherein the one or
more electrodes in the ring member are installed along a
diametrical direction and respective DC voltages applied to the one
or more electrodes are adjusted independently.
5. A ring member in a plasma processing apparatus for performing a
processing on a to-be-treated substrate mounted on a mounting table
in a processing vessel by a plasma of a processing gas, wherein the
ring member is formed of an insulating material and installed to
surround the to-be-treated substrate on the mounting table, wherein
the ring member comprises: one or more electrodes, installed in the
ring member, to each of which a DC voltage is applied to adjust a
plasma sheath region above the ring member.
6. The ring member of claim 5, wherein a first DC voltage is
applied to the one or more electrodes when a first process is
performed on the to-be-treated substrate and a second DC voltage is
applied to the one or more electrodes when a second process is
performed on the to-be-treated substrate.
7. The ring member of claim 6, wherein the first process is etching
of a thin film and the second process is etching of another thin
film from which is different from the thin film in the first
process.
8. The ring member of claim 5, wherein the one or more electrodes
in the ring member are installed along a diametrical direction and
respective DC voltages applied to the one or more electrodes are
adjusted independently.
9. A plasma processing method, comprising the steps of: mounting a
to-be-treated substrate on a mounting table in a processing vessel;
executing a first process on the to-be-treated substrate by
generating plasma in a processing vessel under a condition in which
a first DC voltage is applied to an electrode for adjusting a
plasma sheath region, which is installed in a ring member formed of
an insulating material and installed to surround the to-be-treated
substrate on the mounting table; and executing a second process on
the to-be-treated substrate by generating plasma in the processing
vessel under a condition in which a second DC voltage is applied to
the electrode for adjusting the plasma sheath region.
10. The ring member of claim 5, further comprising: a base
material; and a film formed by thermal spraying of ceramic on a
surface of the base material, wherein the film is formed of ceramic
including at least one kind of element selected from the group
consisting of B, Mg, Al, Si, Ca, Cr, Y, Zr, Ta, Ce and Nd, and at
least a portion of the film is sealed by a resin.
11. The ring member of claim 5, further comprising: a base
material; and a film formed by thermal spraying of ceramic on a
surface of the base material, wherein the film has a first ceramic
layer formed of ceramic including at least one kind of element
selected from the group consisting of B, Mg, Al, Si, Ca, Cr, Y, Zr,
Ta, Ce and Nd and a second ceramic layer formed of ceramic
including at least one kind of element selected from the group
consisting of B, Mg, Al, Si, Ca, Cr, Y, Zr, Ta, Ce and Nd, and at
least a portion of at least one of the first and the second ceramic
layer is sealed by a resin.
12. The ring member of claim 10, wherein the resin is selected from
the group consisting of SI, PTFE, PI, PAI, PEI, PBI and PFA.
13. The ring member of claim 5, further comprising: a base
material; and a film formed by thermal spraying of ceramic on a
surface of the base material, wherein the film is formed of ceramic
including at least one kind of element selected from the group
consisting of B, Mg, Al, Si, Ca, Cr, Y, Zr, Ta, Ce and Nd, and at
least a portion of the film is sealed by a sol-gel method.
14. The ring member of claim 5, further comprising: a base
material; and a film formed by thermal spraying of ceramic on a
surface of the base material, wherein the film has a first ceramic
layer formed of ceramic including at least one kind of element
selected from the group consisting of B, Mg, Al, Si, Ca, Cr, Y, Zr,
Ta, Ce and Nd, and a second ceramic layer formed of ceramic
including at least one kind of element selected from the group
consisting of B, Mg, Al, Si, Ca, Cr, Y, Zr, Ta, Ce and Nd, and at
least a portion of at least one of the first and the second ceramic
layer is sealed by a sol-gel method.
15. The ring member of claim 13, wherein a sealing treatment is
executed by using an element selected from elements in the Group 3a
of the periodic table.
16. The ring member of claim 10, wherein the ceramic is at least
one kind selected from the group consisting of B.sub.4C, MgO,
Al.sub.2O.sub.3, SiC, Si.sub.3N.sub.4, SiO.sub.2, CaF.sub.2,
Cr.sub.2O.sub.3, Y.sub.2O.sub.3, YF.sub.3, ZrO.sub.2, TaO.sub.2,
CeO.sub.2, Ce.sub.2O.sub.3, CeF.sub.3 and Nd.sub.2O.sub.3.
17. The ring member of claim 5, further comprising: a base
material; and a film formed on a surface of the base material,
wherein the film has a main layer formed by thermal spraying of
ceramic and a barrier coat layer formed of ceramic including an
element selected from the group consisting of B, Mg, Al, Si, Ca,
Cr, Y, Zr, Ta, Ce and Nd.
18. The ring member of claim 17, wherein the barrier coat layer is
formed of at least one kind of ceramic selected from the group
consisting of B.sub.4C, MgO, Al.sub.2O.sub.3, SiC, Si.sub.3N.sub.4,
SiO.sub.2, CaF.sub.2, Cr.sub.2O.sub.3, Y.sub.2O.sub.3, YF.sub.3,
ZrO.sub.2, TaO.sub.2, CeO.sub.2, Ce.sub.2O.sub.3, CeF.sub.3 and
Nd.sub.2O.sub.3.
19. The ring member of claim 17, wherein the barrier coat layer is
a thermally sprayed film at least a portion of which is sealed by a
resin.
20. The ring member of claim 19, wherein the resin is selected from
the group consisting of SI, PTFE, PI, PAI, PEI, PBI and PFA.
21. The ring member of claim 17, wherein the barrier coat layer is
a thermally sprayed film at least a portion of which is sealed by a
sol-gel method.
22. The ring member of claim 21, wherein a sealing treatment is
performed by using an element selected from elements in the Group
3a of the periodic table.
23. The ring member of claim 5, further comprising: a base
material; and a film formed on a surface of the base material,
wherein the film has a main layer formed by thermal spraying of
ceramic and a barrier coat layer formed of engineering plastic
formed between the base material and the main layer.
24. The ring member of claim 23, wherein the engineering plastic is
a plastic selected from the group consisting of PTFE, PI, PAI, PEI,
PBI, PFA, PPS, and POM.
25. The ring member of claim 23, wherein the main layer is formed
of at least one kind of ceramic selected from the group consisting
of B.sub.4C, MgO, Al.sub.2O.sub.3, SiC, Si.sub.3N.sub.4, SiO.sub.2,
CaF.sub.2, Cr.sub.2O.sub.3, Y.sub.2O.sub.3, YF.sub.3, ZrO.sub.2,
TaO.sub.2, CeO.sub.2, Ce.sub.2O.sub.3, CeF.sub.3 and
Nd.sub.2O.sub.3.
26. The ring member of claim 5, further comprising: a base
material; and a film formed on a surface of the base material,
wherein the film is formed of ceramic including at least one kind
of element in the Group 3A of the periodic table and at least a
portion of the film is hydrated by vapor or high temperature hot
water.
27. The ring member of claim 5, further comprising: a base
material; and a film formed on a surface of the base material,
wherein the film has a first ceramic layer formed of ceramic
including at least one kind of element in the Group 3a of the
periodic table and a second ceramic layer formed of ceramic
including at least one kind of element in the Group 3a of the
periodic table, and at least a portion of at least one of the first
and the second ceramic layers is hydrated by vapor or high
temperature hot water.
28. The ring member of claim 26, wherein the film is a thermally
sprayed film formed by thermal spraying or a thin film formed by a
thin film formation technique.
29. The ring member of claim 26, wherein the film is formed of
ceramic selected from Y.sub.2O.sub.3, CeO.sub.2, Ce.sub.2O.sub.3
and Nd.sub.2O.sub.3.
30. The ring member of claim 5, further comprising: a base
material; and a film formed on a surface of the base material,
wherein the film has a first ceramic layer formed of ceramic
including at least one kind of element in the Group 3a of the
periodic table and a second ceramic layer formed by thermal
spraying of ceramic, and at least a portion of the first ceramic
layer is hydrated by vapor or high temperature hot water.
31. The ring member of claim 30, wherein the first ceramic layer is
a thermally sprayed film formed by thermal spraying or a thin film
formed by a thin film formation technique.
32. The ring member of claim 30, wherein the first ceramic layer is
formed of ceramic selected from the group consisting of
Y.sub.2O.sub.3, CeO.sub.2, Ce.sub.2O.sub.3 and Nd.sub.2O.sub.3.
33. The ring member of claim 30, wherein the second ceramic layer
is formed of at least one kind of ceramic selected from the group
consisting of B.sub.4C, MgO, Al.sub.2O.sub.3, SiC, Si.sub.3N.sub.4,
SiO.sub.2, CaF.sub.2, Cr.sub.2O.sub.3, Y.sub.2O.sub.3, YF.sub.3,
ZrO.sub.2, TaO.sub.2, CeO.sub.2, Ce.sub.2O.sub.3, CeF.sub.3 and
Nd.sub.2O.sub.3.
34. The ring member of claim 5, further comprising: a base
material; and a film formed on a surface of the base material,
wherein the film has a hydroxide layer formed of hydroxide
including at least one kind of element in the Group 3a of the
periodic table.
35. The ring member of claim 34, wherein the hydroxide layer is a
thermally sprayed film formed by thermal spraying or a thin film
formed by a thin film formation technique.
36. The ring member of claim 34, wherein the hydroxide layer is
formed of hydroxide selected from Y(OH).sub.3, Ce(OH).sub.3 and
Nd(OH).sub.3.
37. The ring member of claim 34, wherein at least a portion of the
hydroxide layer is sealed.
38. The ring member of claim 10, further comprising an anodic
oxidized film formed between the base material and the film.
39. The ring member of claim 38, wherein the anodic oxidized film
is sealed by an aqueous solution of metal salt.
40. The ring member of claim 38, wherein the anodic oxidized film
is sealed by a resin selected from the group consisting of SI,
PTFE, PI, PAI, PEI, PBI and PFA.
41. The ring member of claim 5, wherein the ring member is formed
of a sintered ceramic body including at least one kind of element
in the Group 3a of the periodic table, and at least a portion of
the sintered ceramic body is hydrated by vapor or high temperature
hot water.
42. The ring member of claim 41, wherein the sintered ceramic body
is formed by hydrating ceramic selected from the group consisting
of Y.sub.2O.sub.3, CeO.sub.2, Ce.sub.2O.sub.3 and
Nd.sub.2O.sub.3.
43. The ring member of claim 5, wherein the ring member is formed
of a sintered ceramic body including a hydroxide having at least
one kind of element in the Group 3a of the periodic table.
44. The ring member of claim 43, wherein the hydroxide included in
the sintered ceramic body is selected from the group consisting of
Y(OH).sub.3, Ce(OH).sub.3 and Nd(OH).sub.3.
Description
FIELD OF THE INVENTION
[0001] The present invention relates to a plasma processing
apparatus for performing a process such as an etching process on a
substrate, e.g., a semiconductor wafer, by using plasma.
BACKGROUND OF THE INVENTION
[0002] In manufacturing processes of a semiconductor device,
conventionally, dry etching has been performed on a substrate such
as a semiconductor wafer (hereinafter, referred to as a wafer) for,
e.g., separating capacitors or elements, or forming contact holes.
A single sheet parallel plate type plasma processing apparatus is
known as an apparatus performing such a process (see, e.g.,
reference patents 1 and 2).
[0003] The above-mentioned apparatus will be described briefly with
reference to FIG. 28. The plasma apparatus includes an upper
electrode 11 serving also as a gas shower head and a lower
electrode 12 serving also as a mounting table at an upper side and
lower side of an airtight vessel 1, respectively. Further, a
silicon ring 13 at an inner side and a quartz ring 14 at an outer
side are installed to surround the wafer W on the mounting table
12. The wafer on the mounting table (the lower electrode) is etched
by applying a bias voltage to the lower electrode 12 from a high
frequency power supply 16 and performing vacuum exhaust through a
gas exhaust port 17 to keep a predetermined pressure, while, at the
same time, a high frequency voltage is applied between the upper
and lower electrodes 11 and 12 by a high frequency power supply 15;
and a processing gas from the gas shower head (the upper electrode)
11 is converted into plasma.
[0004] Functions of the silicon ring 13 and the quartz ring 14 will
hereinafter be described. The processing gas arriving at the
proximity of the surface of the wafer W is diffused toward the
periphery of the wafer W and exhausted from outside the periphery
toward the bottom. Therefore, a gas flow of the processing gas at
the peripheral portion (around the periphery) of the wafer W is
different from that at the central portion of the wafer W,
disturbing a balance of a predetermined composition in the
processing gas at the peripheral portion of the wafer W. Further,
the component of impedance, conductance or the like between the
plasma and the lower electrode at an area on which the wafer W is
disposed differs from those at outside the area, respectively. As a
result, the plasma state above a nearby area of the wafer.cndot.s
periphery is different from that above inside of the wafer.cndot.s
periphery.
[0005] On the other hand, high in-surface uniformity of an etching
rate needs to be achieved because of a strong need to form devices
even in the area close to the periphery of wafer W in order to
increase utilization. Accordingly, a ring member (referred to as a
focus ring or the like) formed of a conductor, semiconductor or
dielectric substance is disposed outside the wafer W to adjust the
plasma density above the peripheral portion of the wafer W.
Specifically, a focus ring material is selected; and width, height
or the like of the ring is adjusted according to the material of a
to-be-etched film, the magnitude of a supply power or the like when
installing a focus ring suitable for the process (see, e.g.,
reference patent 3).
[0006] As one example in the above-mentioned reference patents, a
silicon ring is used when etching a silicon oxide film, and, for
example, an insulator, such as quartz or the like, is used when
etching polysilicon.
[0007] reference patent 1: Japanese Patent Laid-Open Publication
No. 8-335568 (pages 3-4, FIG. 2)
[0008] reference patent 2: Japanese Patent Laid-Open Publication
No. 2000-36490 (page 5, FIG. 3)
[0009] reference patent 3: Japanese Patent Laid-Open Publication
No. 8-162444 (page 5, FIG. 2)
PROBLEMS TO BE SOLVED BY THE INVENTION
[0010] From the above, in case of etching multi-layers formed on
the wafer W, different focus rings are required because processing
gases, magnitudes of supply powers or the like vary for each layer
or between some of the layers, and as many chambers need to be
fabricated as the number of different focus rings. Practically, for
example, in order to etch a five-layer film, one chamber is shared
for two films and different chambers are used for the other films.
It is desirable to share a chamber since fundamental components are
identical in etching apparatuses even if etched films are
different, but the above reason prevents the sharing of a
chamber.
[0011] This becomes one factor that makes it difficult to reduce a
footprint (an area occupied by an apparatus), and increases the
cost of manufacturing and operating etching apparatuses with
respect to mass production and management because it increases
variations in apparatuses.
[0012] The present invention is made under such circumstances. It
is, therefore, an object of the present invention to provide an
apparatus and method for plasma processing to promote the sharing
of an apparatus in executing a plurality of different processes.
Another object is to provide a plasma processing apparatus capable
of easily adjusting a plasma state between apparatuses executing
same processes.
SOLUTION
[0013] In accordance with the present invention, there is provided
a plasma processing apparatus for performing a processing on a
to-be-treated substrate mounted on a mounting table in a processing
vessel by plasma of a processing gas, including: a ring member
formed of an insulating material and installed to surround the
to-be-treated substrate on the mounting table; one or more
electrodes installed in the ring member; and a DC power supply for
applying a DC voltage to the one or more electrodes to adjust a
plasma sheath region above the ring member.
[0014] In accordance with a plasma processing apparatus of the
present invention, since a specified DC voltage is applied to an
electrode in the ring member formed of an insulator, thickness of
the ion sheath region at a boundary between the surface of the ring
member and plasma state can be adjusted in each processing
treatment. As a result, a common ring member can be used for a
plurality of different processings, thus promoting the sharing of
an apparatus.
[0015] Further, the plasma processing apparatus of the present
invention may be provided with a means for varying the applied
voltage such that a first DC voltage is applied to the one or more
electrodes when a first process is performed on the to-be-treated
substrate and a second DC voltage is applied to the one or more
electrodes when a second process is performed on the to-be-treated
substrate. In this case, the means may be provided with a storage
area storing process conditions for executing, e.g., the first
process and a second process on the to-be-treated substrate, and
the applied voltage may be converted with reference to data in the
storage area. Furthermore, the first process, for example, is
etching of a thin film and the second process, for example, is
etching of another thin film which is different from the thin film
in the first process. Still further, the one or more electrodes in
the ring member are installed along a diametrical direction and
respective DC voltages applied to the one or more electrodes are
adjusted independently.
[0016] In accordance with another invention, there is provided with
a ring member in a plasma processing apparatus for performing a
processing on a to-be-treated substrate mounted on a mounting table
in a processing vessel by a plasma of a processing gas, wherein the
ring member is formed of an insulating material and installed to
surround the to-be-treated substrate on the mounting table, wherein
the ring member includes: one or more electrodes, installed in the
ring member, to each of which a DC voltage is applied to adjust a
plasma sheath region above the ring member.
[0017] In the ring member, for example, a first DC voltage is
applied to the one or more electrodes when a first process is
performed on the to-be-treated substrate and a second DC voltage is
applied to the one or more electrodes when a second process is
performed on the to-be-treated substrate. In this case, the first
process is etching of a thin film and the second process is etching
of another thin film from which is different from the thin film in
the first process. Further, the one or more electrodes in the ring
member are installed along a diametrical direction and respective
DC voltages applied to the one or more electrodes are adjusted
independently.
[0018] A plasma processing method of the present invention includes
the steps of: mounting a to-be-treated substrate on a mounting
table in a processing vessel; executing a first process on the
to-be-treated substrate by generating plasma in a processing vessel
under a condition in which a first DC voltage is applied to an
electrode for adjusting a plasma sheath region, which is installed
in a ring member formed of an insulating material and installed to
surround the to-be-treated substrate on the mounting table; and
executing a second process on the to-be-treated substrate by
generating plasma in the processing vessel under a condition in
which a second DC voltage is applied to the electrode for adjusting
the plasma sheath region.
[0019] Further, in accordance with a first aspect of the present
invention, there is provided a ring member including: a base
material; and a film formed by thermal spraying of ceramic on a
surface of the base material, wherein the film is formed of ceramic
including at least one kind of element selected from the group
consisting of B, Mg, Al, Si, Ca, Cr, Y, Zr, Ta, Ce and Nd, and at
least a portion of the film is sealed by a resin.
[0020] In accordance with a second aspect of the present invention,
there is provided a ring member including: a base material; and a
film formed by thermal spraying of ceramic on a surface of the base
material, wherein the film has a first ceramic layer formed of
ceramic including at least one kind of element selected from the
group consisting of B, Mg, Al, Si, Ca, Cr, Y, Zr, Ta, Ce and Nd and
a second ceramic layer formed of ceramic including at least one
kind of element selected from the group consisting of B, Mg, Al,
Si, Ca, Cr, Y, Zr, Ta, Ce and Nd, and at least a portion of at
least one of the first and the second ceramic layer is sealed by a
resin.
[0021] According to the first and second aspects of the present
invention, it is preferable that the resin is selected from the
group consisting of SI, PTFE, PI, PAI, PEI, PBI and PFA.
[0022] In accordance with a third aspect of the present invention,
there is provided the ring member including a ring member
including: a base material; and a film formed by thermal spraying
of ceramic on a surface of the base material, wherein the film is
formed of ceramic including at least one kind of element selected
from the group consisting of B, Mg, Al, Si, Ca, Cr, Y, Zr, Ta, Ce
and Nd, and at least a portion of the film is sealed by a sol-gel
method.
[0023] In accordance with a fourth aspect of the present invention,
there is provided a ring member, including: a base material; and a
film formed by thermal spraying of ceramic on a surface of the base
material, wherein the film has a first ceramic layer formed of
ceramic including at least one kind of element selected from the
group consisting of B, Mg, Al, Si, Ca, Cr, Y, Zr, Ta, Ce and Nd,
and a second ceramic layer formed of ceramic including at least one
kind of element selected from the group consisting of B, Mg, Al,
Si, Ca, Cr, Y, Zr, Ta, Ce and Nd, and at least a portion of at
least one of the first and the second ceramic layer is sealed by a
sol-gel method.
[0024] According to the third and fourth aspects of the present
invention, it is preferable that a sealing treatment is executed by
using an element selected from elements in the Group 3a of the
periodic table.
[0025] According to the first to fourth aspects of the present
invention, the ceramic is at least one kind selected from the group
consisting of B.sub.4C, MgO, Al.sub.2O.sub.3, SiC, Si.sub.3N.sub.4,
SiO.sub.2, CaF.sub.2, Cr.sub.2O.sub.3, Y.sub.2O.sub.3, YF.sub.3,
ZrO.sub.2, TaO.sub.2, CeO.sub.2, Ce.sub.2O.sub.3, CeF.sub.3 and
Nd.sub.2O.sub.3.
[0026] In accordance with a fifth aspect of the present invention,
there is provided a ring member including: a base material; and a
film formed on a surface of the base material, wherein the film has
a main layer formed by thermal spraying of ceramic and a barrier
coat layer formed of ceramic including an element selected from the
group consisting of B, Mg, Al, Si, Ca, Cr, Y, Zr, Ta, Ce and
Nd.
[0027] According to the fifth aspect of the present invention, the
barrier coat layer is formed of at least one kind of ceramic
selected from the group consisting of B.sub.4C, MgO,
Al.sub.2O.sub.3, SiC, Si.sub.3N.sub.4, SiO.sub.2, CaF.sub.2,
Cr.sub.2O.sub.3, Y.sub.2O.sub.3, YF.sub.3, ZrO.sub.2, TaO.sub.2,
CeO.sub.2, Ce.sub.2O.sub.3, CeF.sub.3 and Nd.sub.2O.sub.3. Further,
it is preferable that the barrier coat layer is a thermally sprayed
film at least a portion of which is sealed by a resin, and that the
resin is selected from the group consisting of SI, PTFE, PI, PAI,
PEI, PBI and PFA. Furthermore, it is preferable that the barrier
coat layer is a thermally sprayed film at least a portion of which
is sealed by a sol-gel method, and that a sealing treatment is
performed by using an element selected from elements in the Group
3a of the periodic table.
[0028] In accordance with a sixth aspect of the present invention,
there is provided the ring member including: a base material; and a
film formed on a surface of the base material, wherein the film has
a main layer formed by thermal spraying of ceramic and a barrier
coat layer formed of engineering plastic between the base material
and the main layer.
[0029] According to the sixth aspect of the present invention, the
engineering plastic is a plastic selected from the group consisting
of PTFE, PI, PAI, PEI, PBI, PFA, PPS, and POM.
[0030] According to the fifth and sixth aspects of the present
invention, the main layer is formed of at least one kind of ceramic
selected from the group consisting of B.sub.4C, MgO,
Al.sub.2O.sub.3, SiC, Si.sub.3N.sub.4, SiO.sub.2, CaF.sub.2,
Cr.sub.2O.sub.3, Y.sub.2O.sub.3, YF.sub.3, ZrO.sub.2, TaO.sub.2,
CeO.sub.2, Ce.sub.2O.sub.3, CeF.sub.3 and Nd.sub.2O.sub.3.
[0031] In accordance with a seventh aspect of the present
invention, there is provided a ring member including: a base
material; and a film formed on a surface of the base material,
wherein the film is formed of ceramic having at least one kind of
element in the Group 3A of the periodic table and at least a
portion of the film is hydrated by vapor or high temperature hot
water.
[0032] In accordance with an eighth aspect of the present
invention, there is provided the ring member including: a base
material; and a film formed on a surface of the base material,
wherein the film has a first ceramic layer formed of ceramic
including at least one kind of element in the Group 3a of the
periodic table and a second ceramic layer formed of ceramic
including at least one kind of element in the Group 3a of the
periodic table, and at least a portion of at least one of the first
and the second ceramic layers is hydrated by vapor or high
temperature hot water.
[0033] According to the seventh and eighth aspects of the present
invention, the film is a thermally sprayed film formed by thermal
spraying or a thin film formed by a thin film formation technique.
Further, it is preferable that the film is formed of ceramic
selected from Y.sub.2O.sub.3, CeO.sub.2, Ce.sub.2O.sub.3 and
Nd.sub.2O.sub.3.
[0034] In accordance with a ninth aspect of the present invention,
there is provided the ring member including: a base material; and a
film formed on a surface of the base material, wherein the film has
a first ceramic layer formed of ceramic including at least one kind
of element in the Group 3a of the periodic table and a second
ceramic layer formed by thermal spraying of ceramic, and at least a
portion of the first ceramic layer is hydrated by vapor or high
temperature hot water.
[0035] According to the ninth aspect of the present invention, the
first ceramic layer is a thermally sprayed film formed by thermal
spraying or a thin film formed by a thin film formation technique.
Further, it is preferable that the first ceramic layer is formed of
ceramic selected from the group consisting of Y.sub.2O.sub.3,
CeO.sub.2, Ce.sub.2O.sub.3 and Nd.sub.2O.sub.3. Furthermore, it is
preferable that the second ceramic layer is formed of at least one
kind of ceramic selected from the group consisting of B.sub.4C,
MgO, Al.sub.2O.sub.3, SiC, Si.sub.3N.sub.4, SiO.sub.2, CaF.sub.2,
Cr.sub.2O.sub.3, Y.sub.2O.sub.3, YF.sub.3, ZrO.sub.2, TaO.sub.2,
CeO.sub.2, Ce.sub.2O.sub.3, CeF.sub.3 and Nd.sub.2O.sub.3.
[0036] In accordance with a tenth aspect of the present invention,
there is provided the ring member including: a base material; and a
film formed on a surface of the base material, wherein the film has
a hydroxide layer formed of hydroxide including at least one kind
of element in the Group 3a of the periodic table. a base material
and a film formed by spraying ceramic on the surface of the base
material, wherein the film has a hydroxide layer formed of a
hydroxide including at least one element of the Group 3A of the
Periodic table.
[0037] According to the tenth aspect of the present invention, the
hydroxide layer is a thermally sprayed film formed by thermal
spraying or a thin film formed by a thin film formation technique.
Further, it is preferable that the hydroxide layer is formed of
hydroxide selected from Y(OH).sub.3, Ce(OH).sub.3 and Nd(OH).sub.3.
Furthermore, at least a portion of the hydroxide layer is
sealed.
[0038] According to the first to tenth aspects of the present
invention, an anodic oxidized film is formed between the base
material and the film, and in this case, it is preferable that the
anodic oxidized film is sealed by an aqueous solution of metal
salt. Further, the anodic oxidized film may be sealed by a resin
selected from the group consisting of SI, PTFE, PI, PAI, PEI, PBI
and PFA.
[0039] In accordance with an eleventh aspect of the present
invention, there is provided a ring member formed of a sintered
ceramic body including at least one kind of element in the Group 3a
of the periodic table, and at least a portion of the sintered
ceramic body is hydrated by vapor or high temperature hot water. In
this case, it is preferable that the sintered ceramic body is
formed by hydrating ceramic selected from the group consisting of
Y.sub.2O.sub.3, CeO.sub.2, Ce.sub.2O.sub.3 and Nd.sub.2O.sub.3.
[0040] In accordance with a twelfth aspect of the present
invention, there is provided the ring member formed of a sintered
ceramic body including a hydroxide having at least one kind of
element in the Group 3a of the periodic table. In this case, it is
preferable that the hydroxide included in the sintered ceramic body
is selected from the group consisting of Y(OH).sub.3, Ce(OH).sub.3
and Nd(OH).sub.3.
EFFECTS OF THE INVENTION
[0041] In accordance with the present invention, the sharing of an
apparatus can be promoted in a plurality of different processes by
applying a specified DC voltage to an electrode in a ring member
formed of an insulator. Further, for example, when the same process
is executed by using a plurality of the processing vessels, the
adjustment of matching plasma states between these apparatuses can
be performed easily by setting the DC voltage applied to each
electrode as a variable.
[0042] Additionally, in accordance with the present invention, in
the ring member of a structure having a base material and a film
formed by thermal spraying, peeling off of the film formed by
thermal spraying can be suppressed as the surface of the base
material is not exposed to the processing gas or the cleaning fluid
given that several layers function as a barrier.
[0043] Moreover, in accordance with the present invention, the ring
member almost without a release of water in plasma process is
provided, because it can have the structure almost without
adsorption and release of water by performing the hydration
treatment on the ceramic, including at least one element of the
Group 3a of the periodic table, or forming the layer or sintered
body having the hydroxide including at least one element of the
Group 3a of the periodic table.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0044] An embodiment of a plasma processing apparatus in accordance
with the present invention is described with reference to FIG. 1.
Reference numeral 2 refers to an airtight processing vessel formed
of a conductive material, e.g., aluminum, and the processing vessel
2 is grounded. In the processing vessel 2, an upper electrode 3
serving also as a gas shower head, i.e., a gas supply unit for
introducing a predetermined processing gas such as an etching gas,
is disposed to face a lower electrode 4 serving also as a mounting
table for mounting a to-be-processed substrate, e.g., a wafer W,
thereon. Further, a gas exhaust port 21 is installed at the bottom
portion of the processing vessel 2, and a vacuum exhaust unit,
i.e., a vacuum pump 22 such as a turbo molecular pump or a dry
pump, is connected to the gas exhaust port 21 via a gas exhaust
line 21a. Furthermore, an opening 24 for loading/unloading the
wafer W is formed at the sidewall portion of the processing vessel
2 and it can be opened or closed by a gate valve 23.
[0045] At the bottom surface side of the upper electrode 3, a
number of gas diffusion holes 31 are formed to face the wafer W
mounted on the lower electrode 4 and configured to supply uniformly
a processing gas therethrough from an upper gas supply line 32 on
the surface of the wafer W. Further, the gas supply line 32 is
connected at its end to a first gas supplying system 33 for
supplying a first processing gas and a second gas supplying system
34 for supplying a second processing gas different from the first
gas, and either the first gas supplying system 33 or the second gas
supplying system 34 may be selected to supply the processing gas,
for example, by opening/closing operation of valves (not shown).
The first and second gas supplying systems 33 and 34 set forth
herein are intended to supply the first processing gas for
executing a first process and the second processing gas for
executing a second process, respectively, and the first processing
gas (the second processing gas) may represent one or more kind of
gases. Furthermore, the only one gas supply line 32 is shown for
simplicity, but a number of gas supply lines may be installed in
practice, if necessary.
[0046] In addition, the upper electrode 3 is connected to a high
frequency power supply 36 for supplying a power with a frequency
of, e.g., 60 MHz via a low-pass filter 35. Further, an annular
quartz shield ring 37 is inserted surrounding the upper electrode 3
along the outer peripheral portion of the upper electrode 3.
[0047] The lower electrode 4 is connected via a high-pass filter 40
to a high frequency power supply 41 for applying a bias voltage
with a frequency of, e.g., 2 MHz. Further, the lower electrode 4 is
disposed on an elevating mechanism 42 installed at the bottom
portion of the processing vessel 2 so that the lower electrode 4
can be elevated and lowered by the elevating mechanism 42.
Furthermore, a reference numeral 43 refers to a bellows for
preventing plasma from getting under the lower electrode 4.
Further, an electrostatic chuck 44 for attracting and holding the
rear surface of a wafer W by means of electrostatic force is
installed on the upper surface of the lower electrode 4. The
electrostatic chuck 44 includes a sheet-shaped chuck electrode 45;
an insulating layer 46 which covers a surface of the chuck
electrode 45 and is formed of, e.g., polyamide; and a DC power
supply 47 for applying a chuck voltage to the chuck electrode 45.
Further, an annular base plate (not shown) formed of an insulation
member such as quartz is installed around the lower electrode 4 to
protect the electrode against plasma.
[0048] Further, a temperature control unit for controlling the
wafer W to have a predetermined temperature is installed in the
lower electrode 4. The temperature control unit is intended to
regulate the temperature of the wafer W through a rear surface side
by means of a coolant passageway 48, a coolant, a gas supply unit,
a heat transfer gas and the like. To be more specific, the coolant
passageway 48 are installed in the lower electrode 4, and the
coolant circulates in the coolant passageway 48 and an external
coolant temperature control unit (not shown). Furthermore, in a
vacuum atmosphere, formed on the surface of the electrostatic chuck
44 are gas supply holes (not shown) for purging the heat transfer
gas (referred to as a backside gas and the like) such as a helium
gas through a very small gap (a space formed by irregularities due
to the limit of processing precision on the surface) between the
surface of the electrostatic chuck 44 and the rear surface of the
wafer W, and the gas supply holes are connected to, e.g., a gas
supply unit (not shown).
[0049] Moreover, around the electrostatic chuck 44, a focus ring 5,
i.e., a ring member made of an insulating material selected from
alumina, quartz, yttrium oxide and the like, is installed to
surround the periphery of the wafer W attracted and held by the
electrostatic chuck 44. The width of focus ring 5 is set to, e.g.,
50 mm. It is preferable that the focus ring 5 is installed as close
to the outer periphery of the wafer W as possible. For example, the
focus ring 5 is installed such that it is, e.g., not more than 2
mm, preferably 1 mm, spaced from the outer periphery of the wafer
W. Further, an electrode 51 having a shape of, e.g., ring, and
being made of e.g., a metal foil such as Mo, Al or the like or a
tungsten film, is embedded in the focus ring 5 along its
circumference. Furthermore, the electrode 51 is connected to a DC
power supply 52 with an actuator 52a for converting applied
voltages in such a way as to apply a predetermined voltage to the
electrode 51 in each process, for example, apply a first DC voltage
in a first process and a second DC voltage to the electrode 51 in a
second process. The focus ring 5 diffuses plasma which is apt to be
condensed, e.g., at and around the periphery of the wafer W, so
that it improves uniformity of plasma headed for the wafer W.
[0050] Hereinafter, a method for manufacturing the focus ring 5
will be described briefly, and the present invention is not limited
by the manufacturing method. For example, the electrode 51 is first
formed by forming a metal foil by means of screen printing,
film-formation or the like, or by laying a meshed metal member on a
surface of, e.g., a ring-shaped quartz and then the focus ring 5 is
obtained by adhering or welding a thin plate of quartz on the
electrode 51 thereto, or performing thermal straying of yttrium
oxide or the like on the electrode 51. As another method, a
different metal powder which is put on the surface of, e.g.,
ring-shaped alumina, is, for example, pressed to be hardened,
forming the electrode 51 and an alumina powder is put thereon and
sintered to form the focus ring 5.
[0051] Additionally, a reference numeral 6 of FIG. 1 refers to a
controller. The controller 6 has a function to control the
operations of the aforementioned high frequency power supply 36, a
high frequency power supply 41, the actuator 52a, the first gas
supplying system 33, and the second gas supplying system 34. A
control function of the controller 6 will be described again with
reference to FIG. 2. The controller 6 is provided with a computer
60, and a plurality of process recipes are stored in a storage area
61 of the computer 60. Stored in the process recipes are process
conditions corresponding to, e.g., kinds of films to be processed
on the surface of a wafer W, i.e., information of set values such
as an voltage applied to the electrode 51, a process pressure, a
temperature of the wafer W, kinds of processing gases, and a supply
flow rate of a processing gas. A reference numeral 62 refers to a
recipe selecting unit 62 which allows, e.g., an operator to select
a process recipe corresponding to the kind of to-be-treated film.
For example, when films with different process conditions are on
the surface of the wafer W, the first and the second processes are
determined depending on a combination and kinds of the films, and
the process recipes corresponding to the first and the second
processes are selected by the recipe selecting unit 62. Further,
for simplicity, only the first and the second processes are shown,
the process recipes may be prepared corresponding to a third
process, a fourth process, or the like as required, and in this
case, process conditions such as the voltage applied to the
electrode 51 are determined for each process. And, based on
information of a selected process recipe, the actuator 52a is
controlled to apply a predetermined DC voltage to the electrode 51,
and the first and the second gas supplying system 33 and 34 are
controlled during supplying operations to introduce a predetermined
processing gas into the processing vessel 2 with a predetermined
flow rate. Moreover, reference numerals 63 and B refer to a CPU and
a bus, respectively.
[0052] A process of adjusting states of plasma by applying a DC
voltage to the electrode 51 of the focus ring 5 will be described
with reference to FIGS. 3A to 3D. First, when a DC voltage is not
applied to the electrode 51 and a processing gas in the processing
vessel 2 is converted into a plasma as shown FIG. 3A, an ion sheath
region (a plasma sheath region) including high-density positive ion
species 200 is formed at a boundary between the surface of the
wafer W and the plasma P due to higher velocities of electrons
compared with those of positive ion species. Further, an ion sheath
region is also formed at a boundary between the surface of the
focus ring 5 and the plasma P in the same manner, and is thicker
than the ion sheath region on the surface of the wafer W because
the focus ring 5 is made of an insulating material. The ion sheath
region on the surface of the focus ring 5 are formed with various
shapes according to the shapes, material and the like of the focus
ring 5. As described above, when the ion sheath regions are
different in thickness, there is a difference of the plasma density
in the surface of the wafer W, particularly, between the peripheral
portion thereof and the central portion thereof. However, for
example, when a positive DC voltage is applied to the electrode 51
embedded in the focus ring 5, a repulsive force whose magnitude is
suitable for the applied voltage acts between the positive ion
species 200 and the electrode 51, so that the positive ion species
200 in the ion sheath region are returned into the plasma P,
changing the ion sheath region in shape, especially, in thickness.
As a result, the plasma density is changed.
[0053] To be more specific, for example, when the DC voltage
applied to the electrode 51 is low as shown in FIG. 3B, a small
number of positive ion species 200 are returned to the plasma P,
making the ion sheath region thick, so that the plasma P around the
peripheral portion of the wafer W has higher density than that of
the center portion of the wafer W. On the other hand, when the DC
voltage applied to the electrode 51 is high as shown in FIG. 3C,
positive ion species 200 are returned to the plasma P making the
ion sheath region thinner, so that the density of the plasma P
around the periphery portion of the wafer W becomes lower when
compared with the plasma density around the peripheral portion of
the wafer W in FIG. 3B. Further, when the DC voltage applied to the
electrode 51 is still higher as shown in FIG. 3D, the ion sheath
region becomes still thinner than that on the wafer W. Therefore,
the state of the plasma P eventually becomes adjusted if a
predetermined DC voltage is applied to the electrode 51. However,
how to set the practically applied DC voltage for an in-surface
uniform treatment of the wafer W depends on a kind of film to be
etched, supply powers applied to the electrodes 3 and 4, and the
like. Therefore, it is preferable to determine set values for each
process in advance by way of experiments. Further, a negative
voltage may be applied to the electrode 51.
[0054] Hereinafter, a method for processing the wafer W as a
to-be-treated substrate by using the above-mentioned plasma
processing apparatus is described. As an example for processing
processes which are different from each other, an example of
etching a wafer W with a silicon nitride film 65 deposited on a
base film of a silicon film 64 is described as shown in FIG. 4A,
wherein the silicon nitride film has different processing
conditions from those of the silicon film. In this example, a first
process is a process of etching an upper silicon nitride film 65 as
shown in FIG. 4B, and a second process following the first process
is a process of etching a lower silicon film 64 as shown in FIG.
4C. And process recipes corresponding to these processes are
selected by the recipe selecting unit 62 and the process conditions
are set based on information of the selected process recipe.
[0055] First, the wafer W is loaded into the processing vessel 2
from a load-lock chamber (not shown) after the gate valve 23 is
opened. Thereafter the wafer W is mounted on the electrostatic
chuck 44 of the lower electrode 4 via substrate elevating pins (not
shown). Then, the gate valve 23 is closed to make the processing
vessel 2 airtight. Subsequently, the elevating mechanism 42 is
raised, so that the surface of the wafer W is set at a
predetermined height with respect to the upper electrode 3. On the
other hand, the surface of the lower electrode 4 is set at a
predetermined temperature since a coolant circulates in the coolant
passageway 50. And when the wafer W is adsorbed and held to the
surface of the lower electrode 4, a heat transfer gas from the gas
supply holes 51 is supplied into the very small gap between the
surface of the lower electrode 4 and the rear surface of the wafer
W. Therefore, the wafer W is controlled to be kept at a
predetermined temperature by balancing of heat of the gas and heat
transferred from plasma to the wafer W upon generation of plasma as
described below.
[0056] Additionally, the processing vessel 2 is exhausted to a
vacuum state by the vacuum pump 22 while the first etching gas such
as CHF.sub.3 or the like with a given flow rate is introduced
thereto from the first gas supplying system 33 through the gas
supply line 32 and sprayed uniformly on the surface of the wafer W
through the gas diffusion holes 31. So, the processing vessel 2 is
maintained at a vacuum level of, e.g., from 30 to 100 mTorr
(approximately, 4 to 13.3 Pa). The first etching gas forms an air
flow flowing on the surface of the wafer W outward along a
diametrical direction, and is exhausted uniformly from the
periphery of the lower electrode 4.
[0057] Moreover, the first DC voltage, e.g., 1000V, is applied to
the electrode 51. At the same time, a voltage with a high frequency
of, e.g., 60 MHz is applied from the high frequency power supply 34
to the upper electrode 3, e.g., at 1800 Wand a bias voltage of,
e.g., 2 MHz is applied from the high frequency power supply 41 to
the lower electrode 4, e.g., at a range from 1800 to 2250 W with a
timing of 1 second or less. Consequently, the first etching gas is
converted into a plasma while, at the same time, the ion sheath
regions are formed at a boundary between the plasma and the
surfaces of the wafer W and the focus ring 5. As described above,
the ion sheath region above the focus ring 5 has a different
thickness according to the magnitude of a DC voltage applied to the
electrode 51, whereby the plasma above the peripheral portion of
the wafer W has a desired shape. Then, active species of the plasma
move to the ion sheath region and are projected with a high
perpendicularity toward the surface of the wafer W under a high
frequency bias to etch the silicon nitride film 65.
[0058] When the first process, i.e., the etching process of the
silicon nitride film 65, is terminated by doing so, process
conditions are set by reading the process recipe for the second
process to start the second process. First, the processing vessel 2
is opened to exhaust the first etching gas. And the applied voltage
is converted by the actuator 52a such that a voltage of, e.g., 100V
is applied to the electrode 51. Further, the high frequency
voltages applied to the upper and lower electrodes 3 and 4 by the
high frequency power supplies 36 and 41 are adjusted according to
the process recipes. And when the second etching gas, e.g., Cl, is
introduced into the processing vessel 2 from the second gas
supplying system 34, the second etching gas is converted to a
plasma. At this time, the second DC voltage applied to the
electrode 51 controls the thickness of the ion sheath region above
the focus ring 5 and a proper plasma suitable for etching the
silicon film 64 is formed to etch the silicon film 64.
[0059] In accordance with the above-mentioned embodiment, since a
shape of the ion sheath region at the boundary between the surface
of the focus ring 5 and the plasma can be adjusted in each
processing, e.g., according to kinds of films with different
process conditions by applying the predetermined DC voltage to the
electrode 51 of the focus ring 5, the shape of a plasma suitable
for processing the surface of the wafer W uniformly can be formed.
Accordingly, the focus ring 5 may be also used in a plurality of
different processes, thus promoting sharing of the present
apparatus. The sharing of the present apparatus is advantageous
since it contributes to reduction of the footprint of an apparatus
and costs incurred in manufacturing and operating apparatuses.
[0060] Additionally, in accordance with the aforementioned
embodiment, for example, when a plurality of processing vessels 2
are used for the same process, the adjustment of matching plasma
shapes of these apparatuses can be readily performed. For example,
when a plurality of the aforementioned plasma processing
apparatuses described above are installed in a clean room and the
same process is executed in these apparatuses, subtle differences
may exist in process results of the wafers W because assembly of
the apparatuses or the like are different slightly. However, in
such a case, by adjusting voltages applied to the electrode 51, the
characteristics of the apparatuses, i.e., the results of the
process, can be match to each other. Thus, it can be easily
achieved to match the apparatuses. For example, it is preferable
that states of the processed wafers W are checked and an applied
voltage for each apparatus is adjusted finely depending on the
result. Further, the present invention is not limited to promoting
the sharing of an apparatus and may be an apparatus for exclusive
use in a certain type of process, e.g., etching of a specific
film.
[0061] The plasma processing apparatus of the present invention is
not limited to a structure in which two kinds of processes, such as
the first and second processes are performed. And, for example,
when there are five deposition films on the surface of the wafer W,
three, four, or five different processes may be shared according to
the kinds of films with different process conditions. Further, six
and more different processes may be performed. Even with this
structure, a same effect as described above can be obtained.
[0062] In the plasma processing apparatus of the present invention,
the focus ring 5 formed of an insulator is not necessarily disposed
close to the periphery of the wafer W, and a conductor, for
example, a silicon ring 8 may be installed through a circumference
direction between the outer periphery of the wafer W and an inner
periphery of the focus ring 5, as shown in FIG. 5. Even with this
structure, a same effect as described above can be obtained.
[0063] In the plasma processing apparatus of the present invention,
the number of the electrode 51 embedded in the focus ring 5 is not
limited to one. And for example, two ring-shaped electrodes 51a and
51b are disposed in the focus ring 5 on a line along a diametrical
direction and connected to DC power supplies 52A and 52B,
respectively, each of which is provided with an actuator to control
a DC voltage independently. Even with this structure, a same effect
as described above can be obtained. Further, a DC voltage applied
to the outer electrode 52b is lower than that applied to the inner
electrode 51a. Since DC voltages can be set minutely within the
surface of the focus ring 5, for example, it is possible to adjust
the thickness of the ion sheath region with a higher precision.
Furthermore, the processing vessel 2 is not symmetrical in a plan
view due to, for example, a conveying opening formed on a portion
thereof and the like. This may result in a radially nonuniform
plasma or a poor in-surface uniformity along a specific diametrical
direction from the center. In such a case, it is possible that a
specific part of the electrode 51 in the focus ring 5 is separated
from the other part of the electrode 51 along a circumference
direction and voltages applied to both parts may be different from
each other for guaranteeing the radial uniformity of the
plasma.
[0064] In the present invention, it is not limited to the actuator
52a to convert the applied voltage, and for example, DC power
supplies 52 for the first process and the second process are
installed and a switch may be used to convert the applied voltage.
Even with this structure, a same effect as described above can be
obtained. Additionally, etching is employed as an example of the
plasma process in the previous example, but the present invention
can be applied to various plasma processes, for example, CVD and
ashing.
[0065] Finally, an example of a system including the aforementioned
plasma processing apparatus is described with reference to FIG. 7.
A reference numeral 90 in the drawing refers to a first
transferring and mounting chamber 90 connected to cassette chambers
92A and 92B via gate valves G1 and G2 at both sides thereof. The
cassettes 91 capable of receiving a number of wafers W can be
charged into the cassette chambers 92A and 92B. Further,
preliminary vacuum chambers 93A and 93B are connected to the rear
of the first transferring and mounting chamber 90 via gate valves
G3 and G4, respectively. Furthermore, a first transferring and
mounting unit 94 including, e.g., a multi-joint arm is disposed in
the first transferring and mounting chamber 90. A second
transferring and mounting chamber 95 is connected to the rear of
the preliminary vacuum chambers 93A and 93B via gate valves G5 and
G6, and processing vessels 2A, 2B and 2C (2) of the above-mentioned
plasma processing apparatus are respectively connected to the
right, the left and the rear side of the second transferring and
mounting chamber 92 via gate valves G7 to G9 (corresponding to the
gate valve 23). Still further, a second transferring and mounting
unit 96 including, e.g., a multi-joint arm is disposed in the
second transferring and mounting chamber 95.
[0066] In this system, the wafer W in the cassette 91 is conveyed
from the first transferring and mounting chamber 90 to the
preliminary vacuum chamber 93A, and from the preliminary vacuum
chamber 93A to the second transferring and mounting chamber 95. For
example, three kinds of films can be etched in the processing
vessels 2A to 2C, respectively. The wafer W with the three kinds of
films to be etched is loaded into an empty one 2A (2B, 2C) among
the processing vessels 2A to 2C, and the three kinds of films are
etched in the processing vessel 2A (2B, 2C). Then, the wafer W is
unloaded from the processing vessel 2A (2B, 2C) and returned into
the cassette 91 in an order opposite to the aforementioned loading
process.
[0067] FIG. 8 is a vertical cross-sectional view of an example of a
plasma etching processing apparatus, which is a plasma processing
apparatus with a ring member of a plasma processing vessel, a
subject of the present invention. A reference numeral 20 refers to
a vacuum chamber included in the processing vessel, which is formed
of a conductive material, such as aluminum, to have an airtight
structure. And the vacuum chamber 20 is frame-grounded.
Additionally, a cylindrical deposition shield 20a is disposed to an
inner surface of the vacuum chamber 20 to prevent the inner surface
from being damaged by plasma. Further, disposed in the vacuum
chamber 20 are a gas shower head 30 serving also as an upper
electrode and a mounting table 210 serving also as a lower
electrode, which are installed to face each other. And connected to
a lower surface is a gas exhaust pipe 26, which serves as a vacuum
exhaust passageway communicating with a vacuum exhaust unit 25
having, e.g., a turbo molecular pump or a dry pump. Furthermore, an
opening 27 for charging or discharging an object to be processed,
e.g., a semiconductor wafer W, is formed on a sidewall portion of
the vacuum chamber 20 and it can be opened or closed by a gate
valve G. Permanent magnets 28 and 29, having, for example, a shape
of ring, are mounted on an outside of a sidewall portion in such a
manner that the opening 27 is located therebetween.
[0068] The gas shower head 30 has a plural number of holes 38
facing the object W to be processed on the mounting table 210, and
is configured to supply a flow-controlled or pressure-controlled
processing gas coming from an upper gas supply line 39 to a surface
of the object W to be processed uniformly through the corresponding
holes 38.
[0069] Disposed under the gas shower head 30 from about 5 mm to 150
mm apart therefrom, the mounting table 210 includes a cylindrical
main body 211 which is formed of, for example, aluminum having its
surface subjected to alumite treatment and is insulated by an
insulating member 211a from the vacuum chamber 20; an electrostatic
chuck 212 mounted on an upper surface of the main body 211; a
circular focus ring 213 surrounding the electrostatic chuck 212;
and an insulation ring 213a as a circular insulation member
inserted between the focus ring 213 and the main body 211. The
electrostatic chuck 212 includes a sheet-shaped chuck electrode 216
and an insulating layer 215 formed of, e.g., polyimide covering the
surface of the chuck electrode 216. Further, depending on a
process, an insulating or conductive material is selected for the
focus ring 213 to confine or diffuse reactive ions as
aforementioned. An electrode (not shown) having a shape of, e.g.,
ring is embedded in the focus ring 213, as in the embodiment of
FIG. 1. In addition, there are installed the DC power supply 52,
the actuator 52a, and the controller 6 as shown in FIG. 1, and
first and the second DC voltage are applied to the electrode in the
focus ring 213. Moreover, in the same way as described above, an
electrode may be embedded in the insulation ring 213a and a voltage
to be applied to the electrode may be converted by connecting the
electrode to the above or another DC power supply.
[0070] In the mounting table 210, for example, the body 211 thereof
is connected to a high frequency power supply 200 via a capacitor
C1 and a coil L1, and a high frequency power in a range of, e.g.,
from 13.56 MHz to 100 MHz is applied thereto.
[0071] Moreover, installed inside the mounting table 210 are a
temperature control unit 314a of a cooling jacket and a heat
transfer gas supply unit 314b to supply, e.g., He gas to a rear
surface of the object W to be processed. A process surface of the
object W to be processed, held on the mounting table 210, can be
maintained at a desired temperature by activating the temperature
control unit 314a and the heat transfer gas supply unit 314b. The
temperature control unit 314a has an inlet line 315 and a discharge
line 316 for circulating a coolant via the cooling jacket. The
coolant regulated to be kept at an adequate temperature is provided
into the cooling jacket by the inlet line 315, and the coolant
after heat exchange is exhausted to outside by the discharge line
316.
[0072] A ring-shaped exhaust plate 214 having a plurality of
exhaust holes punched therein is disposed between the mounting
table 210 and the vacuum chamber 20 and installed at a position
lower than a surface of the mounting table 210 in such a manner
that it surrounds the mounting table 210. The exhaust plate 214
serves to optimally confine the plasma between the mounting table
210 and the gas shower head 30 and to regulate flows of exhaust
current are regulated. Additionally, protrudently installed in the
mounting table 210 are a plural number, for example, three, of
elevating pins 310 (only two pins are shown) as elevating members
for executing transfer of the object W to be processed between an
external transfer arm (not shown) and the mounting table 210 such
that the elevating pins 310 can be elevated and lowered by a
driving unit 312 through a coupling member 311. A reference numeral
313 refers to a bellows for keeping the space between through holes
of the elevating pins 310 and the atmosphere airtight.
[0073] In the plasma etching processing apparatus, after being
transferred into the vacuum chamber 20 via the gate valve G and the
opening 27, the object W to be processed is first mounted on the
electrostatic chuck 212, the gate valve G is closed, and an inside
of the vacuum chamber 20 is exhausted through the gas exhaust pipe
26 by the vacuum exhaust unit 25 to a predetermined degree of
vacuum. Thereafter, when the processing gas is supplied to the
inside of the vacuum chamber 20, a DC voltage is simultaneously
applied from a DC power supply 217 to a chuck electrode 216, so
that the object W to be processed is electrostatically attracted to
be held by the electrostatic chuck 212. Under the condition, the
high frequency power with a predetermined frequency is applied from
the high frequency power supply 200 to the main body 211 of the
mounting table 210 to thereby generate a high frequency electric
field between the gas shower head 30 and the mounting table 210,
which in turn transforms the processing gas into plasma used for
performing an etching process on the object W to be processed on
the electrostatic chuck 212.
[0074] As the processing gas, a gas including a halogen element,
for example, a fluoride such as C.sub.4F.sub.8 and NF.sub.3, a
chloride such as BCl.sub.3 and SnCl.sub.4, and a bromide such as
HBr, is used. Since a highly strong corrosive environment is
generated inside the vacuum chamber 20 owing to this, a strong
plasma resistance is imperatively required for the members within
the vacuum chamber 20, that is, the internal members of the plasma
processing vessel, for example, the deposition shield 20a, the
exhaust plate 214, the focus ring 213, the shower head 30, the
mounting table 210, the electrostatic chuck 212, and the inner wall
member of the vacuum chamber 20.
[0075] Hereinafter, the above-mentioned ring member will be
described in detail. The ring member to which the structure of the
present invention is applied corresponds to the focus ring 213 and
insulation ring 213a. The insulation ring 213a lies under the focus
ring 213, but it is preferable that a following process is executed
also on the insulation ring 213a because an inner periphery thereof
comes into contact with the processing gas or cleaning fluid.
Further, in the present invention, the following process may be
executed on only the focus ring 213.
[0076] In a conventional case where a base material having a
thermally sprayed film is formed thereon is used as the ring member
of a processing vessel, a thermally sprayed film is bound to be
peeled off. The present inventors have found in their investigation
that the peeling off of the thermally sprayed film on the ring
member of the plasma processing vessel is resulted from the fact
that the processing gas and/or the cleaning fluid infiltrate
through air pores (fine holes) of the thermally sprayed film, a
boundary portion between the thermally sprayed film and the base
material or a portion damaged by plasma and gas to thereby reach
the base material, which ultimately corrodes a surface of the base
material.
[0077] In other words, if a ring member of a processing vessel,
where a plasma treatment has been performed by using a processing
gas including a fluoride, is prepared to analyze a boundary surface
(a base material surface) between the base material and the
thermally sprayed film, F (fluorine) can be found therein. From
this, it is suggested that F reacts on water (OH) to form HF,
whereby the base material surface is corrosively changed (a
corrosion by-product is generated), which leads to the peeling off
of the thermally sprayed film.
[0078] Therefore, it is important that the boundary surface between
the base material and the thermally sprayed film, i.e., the base
material surface, is not exposed to the processing gas or the
cleaning fluid.
[0079] Based on the aforementioned facts, a portion having barrier
function which is hardly corroded is formed at a position between
the surface of the sprayed film and the base material in the ring
member of FIG. 8, even if it is exposed to the processing gas or
the cleaning fluid, thus being capable of preventing the processing
gas or the cleaning fluid from reaching the surface of the base
material.
[0080] By forming the portion having the barrier function by using
a high corrosion-resistant material, the surface of the base
material can be protected from the processing gas or the cleaning
fluid infiltrating through the air pores (the fine holes) of the
thermally sprayed film. Additionally, if the portion having the
barrier function is in contact with the base material, employing a
material with high adhesivity for the portion makes it possible to
protect the surface of the base material from infiltration of the
processing gas or the cleaning fluid through a boundary surface
between the portion having the barrier function and the surface of
the base material.
[0081] Hereinafter, a concrete structure of the ring member will be
described in detail. First, as shown in FIG. 9, a first example of
the ring member basically includes a base material 71 and a film 72
formed on its surface. The film 72 has a main layer 73 formed by
thermal spraying and a barrier coat layer 74 formed between the
base material 71 and the main layer, which has the barrier function
to be rarely corroded even when exposed to the processing gas or
the cleaning fluid.
[0082] Various types of steel including stainless steel (SUS), Al,
Al alloy, W, W alloy, Ti, Ti alloy, Mo, Mo alloy, carbon, oxide or
non-oxide based sintered ceramic body, carbonaceous material and
the like are used properly for the base material 71 as an object on
which the film 72 is constructed.
[0083] It is preferable that the barrier coat layer 74 is formed of
ceramic including at least one kind of element selected from the
group consisting of B, Mg, Al, Si, Ca, Cr, Y, Zr, Ta, Ce and Nd,
and, more particularly, at least one kind of ceramic selected from
the group consisting of B.sub.4C, MgO, Al.sub.2O.sub.3, SiC,
Si.sub.3N.sub.4, SiO.sub.2, CaF.sub.2, Cr.sub.2O.sub.3,
Y.sub.2O.sub.3, YF.sub.3, ZrO.sub.2, TaO.sub.2, CeO.sub.2,
Ce.sub.2O.sub.3, CeF.sub.3 and Nd.sub.2O.sub.3. For example,
products of TOCALO co., LTD. such as
.cndot..cndot.CDC-ZAC.cndot..cndot. and .cndot..cndot.super
ZAC.cndot..cndot. are applicable.
.cndot..cndot.CDC-ZAC.cndot..cndot. is a complex ceramic including
Cr.sub.2O.sub.3 as a main ingredient, and has features such as
imporosity, high hardness, high adhesion and the like.
[0084] On the other hand, .cndot..cndot.super ZAC.cndot..cndot. is
a complex ceramic including SiO.sub.2 and Cr.sub.2O.sub.3 as main
ingredients, and has excellent heat-resistance and
abrasion-resistance in addition to imporosity, high hardness and
high adhesion. It is preferable to form the barrier coat layer 74
by a thermal spraying method. The thermal spraying method is a
method for spraying raw material melted by a heat source such as
combustion gas and electricity on a basic material to form a film.
Further, the barrier layer 74 may be formed by employing a
technique for forming a thin-film such as PVD and CVD method, an
immersion method, a coating method, or the like. The PVD method is
a method of coating various ceramic films coated at low temperature
by employing an ion plating method, while the CVD method is a
method for coating single layer or multiple layers at high
temperature by a thermal chemical vapor deposition. Furthermore,
the method is a method for performing a heat treatment after
immersing various materials being immersed into a resin solution,
and the coating method is a method for performing the heat
treatment at a predetermined temperature after various materials
being coated with a resin solution. It is desirable that the
barrier coat layer 74 is of a thickness ranging from 50 to
100.cndot..cndot..
[0085] In this case, it is preferable to perform sealing by using a
resin on at least one portion of the barrier coat layer 74, e.g.,
on a surface contacted with the base material 71, or on the whole
of the barrier coat layer 74. It is desirable that the resin is
selected from the group consisting of SI, PTFE, PI, PAI, PEI, PBI
and PFA. That is, the barrier coat layer 74 made of ceramic has
porosity with air pores (fine holes) when forming by using the
aforementioned thermal spraying method, but sealing the fine holes
in at least a portion of the porous layer with the resin can
prevent the gas or the cleaning fluid from infiltrating through the
fine holes of the main layer 73 made of the thermally sprayed film,
thus protecting the base material 71 effectively.
[0086] Additionally, SI refers to silicon, PTFE to
polytetrafluoroethylene- , PI to polyimide, PAI to polyamideimide,
PEI to polyetherimide, PBI to polybenzimidazole, and PFA to
perfluoroalkoxyalkane.
[0087] The sealing treatment may be executed by employing a sol-gel
method. The sealing treatment employing the sol-gel method is
performed by sealing with a sol (a colloidal solution) in which
ceramic is dispersed in an organic solvent, and then by the
gelation by heating. Accordingly, the sealing by using ceramic is
substantialized, so that a barrier effect can be improved. It is
preferable that a material selected from the elements of the Group
3a in the periodic table is used in the sealing treatment of this
case. Among them, highly corrosion-resistant Y.sub.2O.sub.3 is
desirable.
[0088] Moreover, engineering plastics may be used as another
alternative material for the barrier coat layer 74. Specifically, a
resin selected from the group consisting of PTFE, PI, PAI, PEI,
PBI, PFA, PPS and POM is preferable and, for example,
.cndot..cndot.Teflon (a registered trademark).cndot..cndot. (PTFE),
a product of DUPONT INC., and the like are applicable. These resins
have excellent adhesivity and chemical resistance which are
sufficient enough to stand against the cleaning fluid in
cleaning.
[0089] Further, PTFE refers to polytetrafluoroethylene, PI to
polyimide, PAI to polyamideimide, PEI to polyetherimide, PBI to
polybenzimidazole, PFA to perfluoroalkoxyalkane, PPS to
polyphenylenesulfide, and POM to polyacetal.
[0090] Furthermore, an anodic oxidized film 75 may be formed
between the base material 71 and the barrier coat layer 74 as
depicted in FIG. 10. In this case, it is desirable that the anodic
oxidized film is formed by organic acid, such as oxalic acid,
chromic acid, phosphoric acid, acetic acid, formic acid or sulfonic
acid, which will result in an oxidized film whose corrosion
resistance is much better than those produced by an anodic
oxidation treatment by sulfuric acid, so that it can further
suppress the corrosion by the processing gas and the cleaning
fluid. It is preferable that the anodic oxidized film 75 is of a
thickness ranging from 10 to 200.cndot..cndot..
[0091] As described above, in case the anodic oxidized film 75 is
formed between the base material 71 and the barrier coat layer 74,
sealing fine holes of the anodic oxidized film 75 can markedly
improve corrosion resistance. In this case, a metal salt sealing is
applicable, in which a material is immersed in hot water including
metal salt such as Ni, so that, in fine holes of the oxidized film,
an aqueous solution of metal salt is hydrolyzed, whereby hydroxide
is precipitated, thus performing sealing.
[0092] Further, the same effect can also be achieved even when the
sealing treatment of the fine holes of the anodic oxidized film 75
is executed by using the resin. It is desirable that the resin is
selected from the group consisting of SI, PTFE, PI, PAI, PEI, PBI
and PFA as described above.
[0093] Furthermore, an anodic oxidized film (KEPLA-COAT: a
registered trademark) with a porous ceramic layer may be used as
the anodic oxidized film 75 formed on the surface of the base
material 71.
[0094] Further, the anodic oxidized film (KEPLA-COAT) is formed by
immersing the base material as an anode in an alkali-based organic
electrolyte to discharge an oxygen plasma therein.
[0095] It is preferable that the main layer 73 as the thermally
sprayed film includes at least one kind of element selected from
the group consisting of B, Mg, Al, Si, Ca, Cr, Y, Zr, Ta, Ce and
Nd, and, to be more specific, it is preferable to include at least
one kind of ceramic selected from the group consisting of B.sub.4C,
MgO, Al.sub.2O.sub.3, SiC, Si.sub.3N.sub.4, SiO.sub.2, CaF.sub.2,
Cr.sub.2O.sub.3, Y.sub.2O.sub.3, YF.sub.3, ZrO.sub.2, TaO.sub.2,
CeO.sub.2, Ce.sub.2O.sub.3, CeF.sub.3 and Nd.sub.2O.sub.3. In this
case, it is desirable that the main layer 73 is of a thickness
ranging from 10 to 500 .mu.m.
[0096] When the ring member with these structures are fabricated,
it is preferable to increase adhesivity of the barrier coat layer
74 or the anodic oxidized film 75 to be formed on the surface of
the base material 71 by executing a blast treatment for blowing up
particles such as Al.sub.2O.sub.3, SiC or sand on the surface of
the base material 71 to make the surface thereof microscopically
uneven. Additionally, etching the surface, e.g., by immersion in a
given medicinal fluid, is allowed as a method for making the
surface uneven, not limiting the method to the aforementioned blast
treatment.
[0097] Next, the aforementioned barrier coat layer 74 is formed
directly on the base material 71 or through the anodic oxidized
film 75 by employing the thermal spraying method or another proper
method. If necessary, the sealing treatment as described above is
executed.
[0098] When the sealing treatment is performed, the aforementioned
resin or sol of ceramic is coated on the surface of the barrier
coat layer 74, or the base material 71 with the barrier coat layer
74 thereon is immersed in a resin sealing material or the sol of
ceramic. In case the sealing is performed by the sol of ceramic,
gelation by heating is followed by heating.
[0099] After forming the barrier coat layer 74, the main layer 73,
a thermally sprayed film, is sequentially formed, wherein the layer
is formed of at least one kind of ceramic selected from the group
consisting of B.sub.4C, MgO, Al.sub.2O.sub.3, SiC, Si.sub.3N.sub.4,
SiO.sub.2, CaF.sub.2, Cr.sub.2O.sub.3, Y.sub.2O.sub.3, YF.sub.3,
ZrO.sub.2, TaO.sub.2, CeO.sub.2, Ce.sub.2O.sub.3, CeF.sub.3 and
Nd.sub.2O.sub.3. In addition to selecting a material with excellent
adhesivity as the barrier coat layer 74, the blast process and the
like may be performed on the surface of the barrier coat layer 74
to further improve adhesivity with the main layer 73.
[0100] As described above, in this example, the problem that the
thermally sprayed film 72 on the base material 71 is peeled off by
generation of the corrosion by-product on the surface of the base
material 71 can be solved by forming the barrier coat layer 74 made
of material with excellent corrosion resistance against the
processing gas including the halogen element or the cleaning fluid
between the main layer 73 as the thermally sprayed film and the
base material 71 in such a way that the surface of the base
material 71 is not exposed to the processing gas (halogen element)
or the cleaning fluid.
[0101] Hereinafter, a second example of the ring member will be
described. In the second example, as shown in FIGS. 11A, 11B and
11C, a film 76 is formed on the surface of the base material 71 by
thermal spraying of ceramic and a sealing-treated portion 76a is
formed in at least a portion of the film 76. The sealing-treated
portion 76a is formed in a side of a portion of the film 76 making
a contact with the base material 71 in an example of FIG. 11A, in a
surface side of the film 76 in the example of FIG. 11B, and in the
whole of the film 76 in the example of FIG. 11C, respectively.
[0102] It is preferable that the film 76 includes at least one kind
of element selected from the group consisting of B, Mg, Al, Si, Ca,
Cr, Y, Zr, Ta, Ce and Nd, and, to be more specific, at least one
kind of ceramic selected from the group consisting of B.sub.4C,
MgO, Al.sub.2O.sub.3, SiC, Si.sub.3N.sub.4, SiO.sub.2, CaF.sub.2,
Cr.sub.2O.sub.3, Y.sub.2O.sub.3, YF.sub.3, ZrO.sub.2, TaO.sub.2,
CeO.sub.2, Ce.sub.2O.sub.3, CeF.sub.3 and Nd.sub.2O.sub.3. In this
case, it is desirable that the film 76 is of a thickness ranging
from 50 to 300 .mu.m. Further, the same material as in the first
example can be used as the base material 71.
[0103] The sealing-treated portion 76a can be formed by sealing by
employing an exactly same resin sealing or sol-gel method as
executed on the barrier coat layer 74 in the first example. As
described above, by forming the sealing-treated portion 76a, the
gas or the cleaning fluid infiltrating through the fine holes of
the film 76, i.e., the thermally sprayed film, can be effectively
blocked, so that the base material 71 can be protected
sufficiently. Because the sealing-treated portion 76a is for
preventing the gas or the cleaning fluid from reaching the base
material 71, any one of those shown in FIGS. 11A to 11C can be
effective. However, forming the sealing-treated portion 76a on the
side of a portion of the film 76 making a contact with the base
material 71 as shown in FIG. 11A is more preferable. That is, if
the ring member of the processing vessel whose thermally sprayed
film has undergone the sealing treatment is used in a plasma
atmosphere obtained by applying high frequency power in a high
vacuum area (e.g., 13.3 Pa), a diluted organic solvent (e.g., ethyl
acetate) in a sealing material may be evaporated, or the sealing
material may be corroded by the plasma, the processing gas and the
like, so that air pores (fine holes) may be formed in the thermally
sprayed film again. Due to these air pores, surface state (e.g.,
temperature and adhesion state of a by-product) of the ring member
of the processing vessel is changed with time, so that it is
possible to exert baleful influence on the process in the
processing vessel. Thus, as shown in FIG. 11A, by avoiding to
perform the sealing treatment on the surface side portion of the
film 76, surface degradation of the film 76 may be suppressed and
the process can be executed stably. Additionally, the
sealing-treated portion 76a may be formed, for example, in the
middle of the film 76, without limiting the positions to those
depicted in FIGS. 11A to 11C. It is desirable that the
sealing-treated portion 76a is from 50 to 100 .mu.m thick.
[0104] Also in this example, as shown in FIG. 12, exactly the same
anodic oxidized film 75 as in the first example can be formed
between the base material 71 and the film 76. Further, in this
case, sealing the anodic oxidized film 75 is preferable and the
same metal salt sealing as mentioned above is available for this
sealing treatment.
[0105] Hereinafter, a third example of the ring member will be
described. In the third example, as shown in FIGS. 13A and 13B, a
film 77 is formed on the surface of the base material 71 by the
thermal spraying of ceramic, the film 77 has a two-layer structure
including a first ceramic layer 78 and a second ceramic layer 79,
and a sealing portion is formed in at least a portion of at least
one of them. In the example of FIG. 13A, a sealing-treated portion
78a is formed in the first ceramic layer 78 located at a surface
side, and in the example of FIG. 13B, a sealing-treated portion 79a
is in the second ceramic layer 79 located at a base material 71
side.
[0106] Both the first ceramic layer 78 and the second ceramic layer
79, being included in the film 77, include at least one kind of
element selected from the group consisting of B, Mg, Al, Si, Ca,
Cr, Y, Zr, Ta, Ce and Nd, and, to be more specific, include at
least one kind of ceramic selected from the group consisting of
B.sub.4C, MgO, Al.sub.2O.sub.3, SiC, Si.sub.3N.sub.4, SiO.sub.2,
CaF.sub.2, Cr.sub.2O.sub.3, Y.sub.2O.sub.3, YF.sub.3, ZrO.sub.2,
TaO.sub.2, CeO.sub.2, Ce.sub.2O.sub.3, CeF.sub.3 and
Nd.sub.2O.sub.3 is preferable. In this case, it is desirable that
the film 77 is from 50 to 300 .mu.m thick. Further, exactly the
same material as in the first example can be used as the base
material 71.
[0107] The sealing-treated portions 78a and 79a may be formed by
employing exactly the same resin sealing or sol-gel method as
executed on the barrier coat layer 74 of the first example. As
described above, by installing the sealing-treated portions 78a and
79a, the gas or the cleaning fluid infiltrating through the fine
holes of the first and second ceramic layers 78 and 79, i.e., the
thermally sprayed films, can be effectively blocked, so that the
base material 71 can be protected sufficiently. Because the
sealing-treated portions 78a and 79a are used for preventing the
gas or the cleaning fluid from reaching the base material 71 as
described above, positions of the sealing-treated portions 78a and
79a are not limited as long as their functions can be realized
effectively, and the whole layer may also be used as the
sealing-treated portion. Further, the sealing-treated portion may
be formed in both sides of the first and second ceramic layers 78
and 79. It is desirable that the sealing-treated portions 78a and
79a are from 50 to 100 .mu.m thick.
[0108] As described above, since, by allowing the film 77 formed on
the base material 71 to have the two-layer structure, materials of
these two layers can be appropriately selected in accordance with
the required corrosion resistance and barrier property, it can be
widely applied with a very high degree of freedom by performing the
sealing treatment at a desired position. For example, the
corrosion-resistance and the barrier property can be much enhanced
if Y.sub.2O.sub.3 is used as the first ceramic layer 78 located
toward the surface, YF.sub.3 or Al.sub.2O.sub.3 is used as the
second ceramic layer 79 located toward the base material 71 and the
sealing is executed in at least a portion of the second ceramic
layer 79.
[0109] As shown in FIG. 14, in this example, exactly the same
anodic oxidized film 75 as in the first example may be formed
between the base material 71 and the film 77. Further, in this
case, sealing the anodic oxidized film 75 is preferable, wherein
the same metal salt sealing and the like as mentioned above and the
like are available.
[0110] In order to confirm the effect of the above structure of the
ring member, following samples were prepared; a first sample was
made by forming a thermally sprayed film of Y.sub.2O.sub.3 on a
base material of Al alloy, a second sample was made by forming a
thermally sprayed film of Y.sub.2O.sub.3 through a resin (PTFE)
barrier coat layer on a base material of Al alloy; and a third
sample was made by forming a thermally sprayed film of
Y.sub.2O.sub.3on on a base material of Al alloy and sealing some of
the thermally sprayed film with the resin. Then, the surface states
of the thermally sprayed films were subject under plasma
environment after dropping a HF solution on the surfaces of the
first to the third samples to compare with each other. To be more
specific, the samples were put under a plasma atmosphere of a
CF-based gas for three minutes after dropping a 38% HF solution of
10 .mu.l on each surface of the samples and being heated at
50.degree. C. for three hours. As a result, it was found that a
crack had developed on the whole surface of the first sample on
which a countermeasure for peeling off of the thermally sprayed
film had not been executed, while no crack had developed and the
surfaces of the base materials were protected by preventing the
infiltration of hydrofluoric fluid in the second sample where the
barrier coat layer was formed between the base material and the
thermally sprayed film and the third sample where some of the
thermally sprayed film was sealed by the resin.
[0111] In a case where Al.sub.2O.sub.3 and Y.sub.2O.sub.3 are used
as the ring member, various problems occur since a large amount of
water is absorbed due to high reactivity on water in the air when
the vacuum chamber, i.e., the processing vessel, is open to
atmosphere or undergoes the wet cleaning. However, the present
inventors have found in their investigation that these problems can
be solved by performing hydration treatment on ceramic, such as
Y.sub.2O.sub.3, including an element of the Group 3a in the
Periodic table or forming a hydroxide including these elements.
[0112] Based on the above description, in the ring member (in this
example, the focus ring 213 and the insulation ring 213a) in FIG.
8, a hydrated portion is formed of ceramic including the element of
the Group 3a in the periodic table, or at least a portion of that
is formed of hydroxide including that element.
[0113] In the ring member of the plasma processing vessel made in
this way, release of water hardly occurs during the plasma process
since the structure makes it difficult to adsorb water and release
water therefrom.
[0114] First, in a fourth example of the ring member, as shown in
FIG. 15, a film 82 made of ceramic including an element of the
Group 3a in the periodic table is formed on a base material 81 and
a hydration-treated portion 82a is formed, for example, at least in
a surface portion of the film 82.
[0115] Various types of steel including stainless steel (SUS), Al,
Al alloy, W, W alloy, Ti, Ti alloy, Mo, Mo alloy, carbon, oxide and
non-oxide based sintered ceramic body, carbonaceous material and
the like are used properly for the base material 81 in a similar
manner to the base material 71.
[0116] The film 82 may be made of ceramic including an element of
the Group 3a in the periodic table, but it is preferable to be made
of oxide including the element of the Group 3a in the Periodic
table. Further, among these, Y.sub.2O.sub.3, CeO.sub.2,
Ce.sub.2O.sub.3 and Nd.sub.2O.sub.3 are preferable and, among them,
Y.sub.2O.sub.3 is particularly desirable since it has been
conventionally and widely used and has high corrosion
resistance.
[0117] The film 82 can be formed preferably by employing a
technique for forming a thin-film such as the thermally sprayed
method and the PVD and CVD method. Further, it is possible to form
the film by employing the immersion method, the coating method or
the like.
[0118] The hydration-treated portion 82a can be formed, for
example, by making the film 82 react on water vapor or high
temperature hot water to cause a hydration reaction. In case of
using Y.sub.2O.sub.3 as the ceramic, the reaction such as an
equation (1) below occurs:
Y.sub.2O.sub.3+H.sub.2O.fwdarw.Y.sub.2O.sub.3.(H.sub.2O)n.fwdarw.2(YOOH).f-
wdarw.Y(OH).sub.3 (1)
[0119] wherein mantissa is not considered in Eq. (1).
[0120] As represented in the equation (1), by the hydration
treatment, Y hydroxide is formed in the end. In case of another
element of the Group 3a in the periodic table, such hydroxide is
formed by almost the same reaction. Y(OH).sub.3, Ce(OH).sub.3 and
Nd(OH).sub.3 are preferable for such hydroxide.
[0121] In order to confirm this, samples having the thermally
sprayed film of Y.sub.2O.sub.3 on the base material were prepared,
and X-ray diffraction measurement was performed on the one sample
which was hydrated by immersion in high temperature hot water
maintained at a temperature of 80.degree. C. for 150 hours and then
dehydrated at room temperature, and on another sample on which
these treatments were not performed. The comparison result showed
that Y(OH).sub.3 was detected only in the sample on which the
hydration treatment was performed, confirming that hydroxide was
formed by the hydration treatment, as shown in FIGS. 16A and
16B.
[0122] The hydroxide of the element of the Group 3a in the periodic
table is highly stable and has features that chemically adsorbed
water is difficult to be separated and it is difficult to adsorb
water. The problem caused by water during the process can be
avoided by forming the hydroxide like this by the hydration
treatment.
[0123] In order to confirm an effect of the hydration treatment,
after preparing samples which had a 200 .mu.m thick film of
thermally sprayed Y.sub.2O.sub.3 on the base material, one sample
was treated by boiling water for three hours, while another sample
was not treated by boiling water. IPA was sprayed on both of them.
IPA spraying becomes an acceleration test since IPA has higher
adsorption than water. The test showed that IPA was adsorbed to the
non-hydrated sample but no adsorption occurred to the hydrated
sample, as shown in FIG. 17. From this, it was confirmed that the
hydration treatment made it difficult for adsorption to occur.
[0124] Next, in the same way, after preparing samples which had a
200 Am thick film of thermally sprayed Y.sub.2O.sub.3 on the base
material, a sample was treated by boiling water for three hours
while another sample was not treated by boiling water. Both of them
were coated by the resin and cut to check cross sections thereof.
The result, depicted in FIGS. 18A and 18B, showed that there were
no differences on the surface states of the both samples. However,
for the sample without the treatment, the film was transparent on
the whole, confirming that the resin penetrated through the whole
film. On the other hand, for the treated sample, only small portion
close to the surface was transparent and the inside was white in
the treated sample, indicating that the resin was hardly penetrated
to the inside of the treated sample. That verifies that the
hydration treatment causes hydrophobic property. Further, as shown
in FIG. 18C, when the film about 20 .mu.m thick from the surface
was removed after the hydration treatment, it was found that the
removed portion was transparent and hydrophobic property was
reduced.
[0125] Moreover, an effect of H.sub.2O on a Y.sub.2O.sub.3 surface
has been described in detail in a paper entitled "Specific
Adsorption Behavior of Water on a Y.sub.2O.sub.3 Surface" of Kuroda
et al. disclosed on pages 6937 to 6947 of Langmuir, Vol. 16, No.
17, 2000.
[0126] Hereinafter, the hydration treatment will be described in
detail. The hydration treatment can be executed by heat treatment
in an environment containing abundant water vapor or treatment in
boiling water. Several water molecules can be attracted toward
neighborhood of, e.g., an yttrium oxide (Y.sub.2O.sub.3) molecule
to be combined together into one stable molecule cluster. At this
time, main parameters include partial pressure of water vapor,
temperature and time of heat treatment and the like. For example, a
stable hydroxide can be formed by heat treatment for about 24 hours
in a furnace with temperature ranging from about 100 to about
300.degree. C. under relative humidity which is equal to or greater
than 90%. If relative humidity and temperature of heat treatment
are low, it is preferable to prolong the time of treatment.
Treatment at high temperature and high pressure is desirable for
efficient hydration treatment. Because the hydration reaction on
the surface of yttrium oxide can proceed basically even at room
temperature if executed for a long time, the same final state can
be obtained also under other conditions besides the above
condition. Further, in the hydration treatment, using water
including ion (alkali water with a pH higher than 7) results in a
hydroxide with a better hydrophobic property than for the case
using pure water.
[0127] Furthermore, not limited to the hydration treatment, other
methods, for example, forming hydroxide at a raw material step, may
be employed as long as the hydroxide is formed finally. In case of
making the film by the thermal spraying method, because the raw
material is exposed to high temperature, there is a concern that
the hydroxide may be changed into an oxide if hydroxide is formed
at the raw material step, but, even in this case, a hydroxide film
can be formed by thermally spraying under a condition of high
humidity. Instead of forming the hydration-treated portion like
this, the hydroxide may be formed directly by using a different
method.
[0128] The hydration-treated portion or hydroxide layer should be
formed in a surface portion of the film 82 in order that the film
82 has a structure difficult to adsorb water and be separated from
water. It is desirable that the hydration-treated portion or
hydroxide film of this case is equal to or greater than 100 .mu.m
thick and the thickness thereof is set optimally depending on usage
place.
[0129] Densification is also promoted by the hydration treatment
for the ceramic including the element of the Group 3a in the
Periodic table. For example, the Y.sub.2O.sub.3 film formed by the
thermal spraying is porous before the hydration treatment as shown
FIG. 19A, but it is densified by the hydration treatment as shown
in FIG. 19B. By becoming dense like this, the same barrier effect
as in the first embodiment is obtained in addition to the above
effect.
[0130] In view of obtaining only the barrier effect, the
hydration-treated portion 82a of the hydroxide formed by the
hydration treatment need not be located necessarily in the surface
portion of the film 82, and it may be formed at any position of the
film 82. In a case of forming the hydroxide layer of the hydroxide
formed by another method, it is desirable to perform the sealing by
the resin or sol-gel method as mentioned above. In this example, in
a similar way to the aforementioned embodiment, as depicted in FIG.
20, exactly the same anodic oxidized film 83 may be formed between
the base material 81 and the film 82. Further, it is preferable to
perform the sealing treatment on the anodic oxidized film 83, and,
as this sealing treatment, the metal salt sealing identical to the
aforementioned one is available.
[0131] Hereinafter, a fifth example of the ring member will be
described. In the fifth example, as shown in FIGS. 21A and 21B, a
film 84 is formed in the surface of the base material 81, it has
two-layer structure including a first ceramic layer 85 and a second
ceramic layer 86, and a hydration-treated portion is formed in at
least a portion of at least one of the first and the second ceramic
layer. A hydration-treated portion 85a is formed in a surface side
of the first ceramic layer 85 in the example of FIG. 21A, and a
hydration-treated portion 86a is formed in a side of the second
ceramic layer 86 making a compact with the base material 81 in the
example of FIG. 21B.
[0132] Hereinafter, a fifth example of the ring member is
described. In the fifth example, as shown in FIGS. 21A and 21B, a
film 84 is formed on the surface of the base material 81, and it
has double layers including a first ceramic layer 85 and a second
ceramic layer 86, and a hydration treatment portion formed in at
least a portion of at least one of the first and second ceramic
layers. A hydration treatment portion 85a is formed at the first
ceramic layer 85 on the top (the surface) of the film 84 in the
example of FIG. 21A, and a hydration-treated portion 86a is formed
at the second ceramic layer 86 on the bottom of the film 84 in
contact with the base material 81 in the example of FIG. 21B.
[0133] Both the first ceramic layer 85 and the second ceramic layer
86 included in the film 84 are formed of ceramic including an
element of the Group 3a in the periodic table and, an oxide
including an element of the Group 3a in the periodic table is
preferable. Among them, Y.sub.2O.sub.3, CeO.sub.2, Ce.sub.2O.sub.3
and Nd.sub.2O.sub.3 are preferable, and particularly,
Y.sub.2O.sub.3 is preferable. Furthermore, exactly the same
material as in the fourth example can be used as the base material
81.
[0134] These first and second ceramic layers 85 and 86 can be
formed preferably, in a similar way as the film 82 in the first
example, by employing the technique for forming a thin-film such as
the thermal spraying method, the PVD method or the CVD method.
Further, it is possible to form them by employing an immersion
method, a coating method, or the like.
[0135] The hydration-treated portions 85a and 86a can be formed in
exactly the same way as the hydration-treated portion 82a in the
fourth example. If the hydration-treated portion is disposed in the
surface portion of the film 84 as shown in FIG. 21A, a structure
making adsorbing water or being separated from water difficult can
be formed, and, if the hydration-treated portion is in the film 84,
as shown in FIG. 21B, the barrier effect can be made work
effectively. In order to form the hydration-treated portion in the
film 84, after fabricating the second ceramic layer 86 on the base
material 81, the hydration treatment is performed and the first
ceramic layer 85 is formed. It is desirable that the
hydration-treated portions 85a and 86a are of thickness equal to or
greater than 100 .mu.m.
[0136] By forming the film 84 on the base material 81 in the
two-layer structure like this, it can widen the scope of its
applicability with large degree of freedom, since materials of the
two layers and position of the hydration treatment can be selected
to better accommodate various specific requirements of the
situation.
[0137] In this example, the same anodic oxidized film 83 as in the
first example may be formed between the base material 81 and the
film 84, as shown in FIG. 22.
[0138] Hereinafter, a sixth example of the ring member will be
described. In the sixth example, as shown in FIG. 23, a film 87 is
formed on the surface of the base material 81, and it has a first
ceramic layer 88 formed of ceramic including at least one kind of
element of the Group 3a in the periodic table; and a second ceramic
layer 89 formed by thermal spraying of ceramic, wherein a
hydration-treated portion 88a formed in a surface portion of the
first ceramic layer 88.
[0139] As the ceramic of the first ceramic layer 88 including the
element of the Group 3a in the periodic table, the oxide including
the element of the Group 3a in the periodic table is preferable.
Among them, Y.sub.2O.sub.3, CeO.sub.2, Ce.sub.2O.sub.3 and
Nd.sub.2O.sub.3 are preferable and Y.sub.2O.sub.3 is particularly
preferable. It is desirable that the first ceramic layer 88 is of
thickness ranging from 100 to 300 .mu.m. The first ceramic layer 88
can be formed preferably, in a similar way to the film 82 in the
fourth example, by employing the technique for forming a thin-film
such as the thermally spraying method, the PVD method and the CVD
method. Further, it is possible to form the layer by employing the
immersion method, the coating method, or the like.
[0140] It is preferable that the second ceramic layer 89 includes
at least one kind of element selected from the group consisting of
B, Mg, Al, Si, Ca, Cr, Y, Zr, Ta, Ce and Nd, and, to be more
specific, at least one kind of ceramic selected from the group
consisting of B.sub.4C, MgO, Al.sub.2O.sub.3, SiC, Si.sub.3N.sub.4,
SiO.sub.2, CaF.sub.2, Cr.sub.2O.sub.3, Y.sub.2O.sub.3, YF.sub.3,
ZrO.sub.2, TaO.sub.2, CeO.sub.2, Ce.sub.2O.sub.3, CeF.sub.3 and
Nd.sub.2O.sub.3. It is desirable that the second ceramic layer 89
is of thickness ranging from 50 to 300 .mu.m. Further, exactly the
same material as in the fourth example can be used as the base
material 81.
[0141] The hydration-treated portion 88a can be formed in the same
way as the hydration-treated portion 82a in the fourth example.
Because the hydration-treated portion is formed in the surface
portion of the film 87, the film 87 can be made to have a structure
difficult to adsorb water and release water. In addition, the
barrier effect may be made work effectively by forming the
hydration-treated portion 88a inside the first ceramic layer 88. It
is desirable that the hydration-treated portion 88a is of thickness
equal to or greater than 100 .mu.m.
[0142] As shown in FIG. 24, it is preferable to form a
sealing-treated portion 89a in the second ceramic layer 89. The
sealing-treated portion 89a can be formed by using the same resin
sealing or sol-gel method as described in the above-mentioned first
to third embodiments. The base material 81 can be protected
sufficiently by installing the sealing-treated portions 89a since
the gas or the cleaning fluid infiltrating through fine holes of
the second ceramic layer 89, i.e., the thermally sprayed film, can
be blocked effectively. Further, the sealing-treated portion 89a
can be formed at any position of the second ceramic layer 89.
[0143] By forming the structures as shown in FIGS. 23 and 24, the
film 87 can have a structure difficult to adsorb water and release
water by the hydration-treated portion 88a of the first ceramic
layer 88, simultaneously having excellent corrosion-resistance.
Besides, the base material 81 can be protected effectively by the
barrier effect of the second ceramic layer 89. Particularly, in the
structure shown in FIG. 24, the existence of the sealing-treated
portion 89a can further enhance the barrier effect.
[0144] Moreover, as shown in FIG. 25, the first ceramic layer 88
and the second ceramic layer 89 may be installed in a reversed
order. In this case, protection effect on the base material 81 may
be improved since the hydration-treated portion 88a of the first
ceramic layer 88 laid out next to the base material 81 can enhance
the barrier effect effectually.
[0145] In this example, as shown in FIG. 26, the same anodic
oxidized film 83 as in the first example may be formed between the
base material 81 and the film 87.
[0146] Hereinafter, a seventh example of the ring member will be
described. In the ring member in the seventh example, as shown in
FIG. 27, a hydration-treated portion 98 is formed in a surface
portion of a sintered ceramic body 97 including the element of the
Group 3a in the periodic table. The hydration-treated portion 98
can be formed in the same manner as in the above-mentioned
embodiment, and the hydration treatment generates the hydroxide
including the element of the Group 3a in the periodic table.
[0147] The hydration-treated portion 98 is formed in the surface
portion, so that a structure making it difficult to adsorb water or
release water is formed. It is desirable that the hydration-treated
portion 98 or the hydroxide film of this case is of thickness equal
to or greater than 100 .mu.m.
[0148] In the seventh embodiment, as in the fourth to the sixth
embodiments, ceramic including an element of the Group 3a in the
periodic table is preferably oxide including an element of the
Group 3a in the periodic table. Among them, Y.sub.2O.sub.3,
CeO.sub.2, Ce.sub.2O.sub.3 and Nd.sub.2O.sub.3 are preferable and,
in particular, Y.sub.2O.sub.3 is desirable.
[0149] Additionally, in the above embodiments, the case of applying
the present invention to the ring members (the focus ring 213 and
insulation ring 213a) of a parallel plate plasma etching apparatus
of a magnetron type using a permanent magnet has been described as
an example, but the present invention is not limited to the
apparatus of this structure, and can be applied to the plasma
processing vessel used in a parallel plate plasma etching apparatus
having no magnetron; another plasma etching processing apparatus
and etching apparatus such as an inductively coupled one; and an
apparatus executing various plasma processes such as an ashing and
a film forming process in addition to etching.
[0150] While the invention has been shown and described with
respect to the preferred embodiments, it will be understood by
those skilled in the art that various changes and modifications may
be without departing from the spirit and scope of the invention as
defined in the following claims.
INDUSTRIAL APPLICABILITY
[0151] A plasma processing apparatus in accordance with the present
invention is applicable to an apparatus executing plasma processes
such as etching, e.g., on a semiconductor wafer and the like,
because plasma states can be adjusted by applying a specified
voltage to an electrode in a ring member. Further, the ring member
of the present invention is desirable for a plasma process in a
highly corrosive atmosphere, in particular, since a film formed on
a base material is formed of ceramic with a high
corrosion-resistance and a portion which functions as a barrier is
installed. Furthermore, it is preferable as the ring member
subjected to water problems, because its structure is stable in
water by executing a hydration treatment on the ceramic including
an element of the Group 3A of the periodic table.
BRIEF DESCRIPTION OF THE DRAWINGS
[0152] FIG. 1 shows a vertical cross-sectional view of a plasma
processing apparatus in accordance with an embodiment of the
present invention;
[0153] FIG. 2 illustrates an explanatory diagram of a controller of
the plasma processing apparatus;
[0154] FIGS. 3A to 3D describe explanatory diagrams of plasma
states in a plasma process using the plasma processing
apparatus;
[0155] FIGS. 4A to 4C offer explanatory diagrams of multi-layers
etched by using the plasma processing apparatus;
[0156] FIG. 5 provides an explanatory diagram of another embodiment
of the present invention;
[0157] FIG. 6 presents an explanatory diagram of still another
embodiment of the present invention;
[0158] FIG. 7 depicts a plasma processing system including the
plasma processing apparatus in accordance with an embodiment of the
present invention;
[0159] FIG. 8 represents a vertical cross-sectional view of a
plasma processing apparatus mounted with a ring member in
accordance with an embodiment of the present invention;
[0160] FIG. 9 depicts a cross-sectional view of a layer structure
in a first example of the ring member in accordance with the
present invention;
[0161] FIG. 10 sets forth a cross-sectional view of an example of
adding an anodic oxidized film to the structure of FIG. 9;
[0162] FIGS. 11A to 11C show cross-sectional views of layer
structures in a second example of the ring member in accordance
with an embodiment of the present invention;
[0163] FIG. 12 illustrates a cross-sectional view of an example of
adding the anodic oxidized film to the structures of FIGS. 11A to
11C;
[0164] FIGS. 13A and 13B describe cross-sectional views of layer
structures in a third example of the ring member in accordance with
the embodiment of the present invention;
[0165] FIG. 14 offers a cross-sectional view of an example of
adding the anodic oxidized film to the structures of FIGS. 13A and
13B;
[0166] FIG. 15 provides a cross-sectional view of a layer structure
in a first example of the ring member in accordance with the
embodiment of the present invention;
[0167] FIGS. 16A and 16B present patterns of X-ray analysis when
hydration treatment is executed on a Y.sub.2O.sub.3 film and when
the hydration treatment is not executed on the Y.sub.2O.sub.3
film;
[0168] FIG. 17 depicts adsorption of IPA when the hydration
treatment is executed on the Y.sub.2O.sub.3 film and when the
hydration treatment is not executed on the Y.sub.2O.sub.3 film;
[0169] FIGS. 18A to 18C illustrate infiltrations of resin when the
hydration treatment is executed on the Y.sub.2O.sub.3 film and when
the hydration treatment is not executed on the Y.sub.2O.sub.3
film;
[0170] FIGS. 19A and 19B are photographs of a scanning electron
microscope showing layer states before the hydration treatment and
after the hydration treatment;
[0171] FIG. 20 describes a cross-sectional view of an example of
adding an anodic oxidized film to the structure of FIG. 15;
[0172] FIGS. 21A and 21B offer cross-sectional views of layer
structures in a second example of the ring member in accordance
with an embodiment of the present invention;
[0173] FIG. 22 provides a cross-sectional view of an example of
adding the anodic oxidized film to the structure of FIGS. 21A or
21B;
[0174] FIG. 23 presents a cross-sectional view of a layer structure
in a third example of the ring member in accordance with an
embodiment of the present invention;
[0175] FIG. 24 depicts a cross-sectional view of another layer
structure in the third example of the ring member in accordance
with an embodiment of the present invention;
[0176] FIG. 25 represents a cross-sectional view of still another
layer structure in the third example of the ring member in
accordance with an embodiment of the present invention;
[0177] FIG. 26 sets forth a cross-sectional view of an example of
adding the anodic oxidized film to the structure of FIG. 16;
[0178] FIG. 27 illustrates a schematic diagram of the ring member
in accordance with an embodiment of the present invention; and
[0179] FIG. 28 is an explanatory drawing of a conventional plasma
processing apparatus.
REFERENCE CHARACTERS
[0180] 2 processing vessel
[0181] 22 vacuum pump
[0182] 3 upper electrode
[0183] 33 first gas supplying system
[0184] 34 second gas supplying system
[0185] 4 lower electrode
[0186] 44 electrostatic chuck
[0187] 5 focus ring
[0188] 51 electrode
[0189] 52a actuator
[0190] 6 controller
[0191] 20 vacuum chamber
[0192] 20a deposition shield
[0193] 30 gas shower head
[0194] 210 mounting table
[0195] 212 electrostatic chuck
[0196] 213 focus ring
[0197] 214 exhaust plate
[0198] 71, 81 base material
[0199] 72, 76, 77, 82, 84, 87 film
[0200] 74 barrier coat layer
[0201] 75, 83 anodic oxidized film
[0202] 76a, 78a, 79a sealing-treated portion
[0203] 82a, 86a, 88a, 98 hydration-treated portion
* * * * *