U.S. patent application number 17/407668 was filed with the patent office on 2021-12-09 for component and semiconductor manufacturing device.
The applicant listed for this patent is KYOCERA Corporation. Invention is credited to Takashi HINO, Tetsuo INOUE, Shuichi SAITO.
Application Number | 20210381094 17/407668 |
Document ID | / |
Family ID | 1000005787422 |
Filed Date | 2021-12-09 |
United States Patent
Application |
20210381094 |
Kind Code |
A1 |
HINO; Takashi ; et
al. |
December 9, 2021 |
COMPONENT AND SEMICONDUCTOR MANUFACTURING DEVICE
Abstract
A component includes a film containing polycrystalline yttrium
oxide. In an X-ray diffraction pattern of the film, a ratio
I.sub.m/I.sub.c of a maximum intensity I.sub.m of a peak attributed
to monoclinic yttrium oxide to a maximum intensity I.sub.c of a
peak attributed to cubic yttrium oxide satisfies an expression:
0.ltoreq.I.sub.m/I.sub.c.ltoreq.0.002.
Inventors: |
HINO; Takashi; (Yokohama,
JP) ; INOUE; Tetsuo; (Yokohama, JP) ; SAITO;
Shuichi; (Yokohama, JP) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
KYOCERA Corporation |
Kyoto-shi |
|
JP |
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|
Family ID: |
1000005787422 |
Appl. No.: |
17/407668 |
Filed: |
August 20, 2021 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
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16777371 |
Jan 30, 2020 |
11111573 |
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17407668 |
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PCT/JP2018/028376 |
Jul 30, 2018 |
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16777371 |
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Current U.S.
Class: |
1/1 |
Current CPC
Class: |
C30B 29/22 20130101;
C30B 28/14 20130101; C30B 25/10 20130101; H01L 21/3065 20130101;
C23C 14/083 20130101; C30B 29/02 20130101; C30B 28/12 20130101;
C30B 28/00 20130101; C30B 25/00 20130101; Y10T 428/12618 20150115;
C30B 29/16 20130101; Y10T 428/12611 20150115 |
International
Class: |
C23C 14/08 20060101
C23C014/08; H01L 21/3065 20060101 H01L021/3065 |
Foreign Application Data
Date |
Code |
Application Number |
Jul 31, 2017 |
JP |
2017-147757 |
Claims
1. A method of manufacturing a component to comprise a film
containing crystalline yttrium oxide, wherein in an X-ray
diffraction pattern of the film, a ratio I.sub.m/I.sub.c of a
maximum intensity I.sub.m of a peak attributed to monoclinic
yttrium oxide to a maximum intensity I.sub.c of a peak attributed
to cubic yttrium oxide satisfies an expression:
0.ltoreq.I.sub.m/I.sub.c.ltoreq.0.002, wherein the method
comprises: repeatedly performing a sputtering process followed by
an oxidation process, wherein the oxidation process consists of
heating the film in an oxygen-containing atmosphere at a
temperature of 1000.degree. C. or less for one second or less.
2. The method according to claim 1, wherein the X-ray diffraction
pattern does not have a peak attributed to yttrium oxide whose
crystal structure is different from a crystal structure of the
cubic yttrium oxide.
3. The method according to claim 1, wherein a thickness of the film
is 100 .mu.m or less.
4. The method according to claim 1, wherein a thickness of the film
is 10 .mu.m or more and 50 .mu.m or less.
5. The method according to claim 1, wherein an average grain
diameter of the crystalline yttrium oxide is 10 nm or less.
6. The method according to claim 1, wherein in an observation image
obtained by observing a cross section in a thickness direction of
the film by using a scanning electron microscope at 10000
magnification, a pore is not present or a maximum diameter of a
pore is 10 nm or less.
7. The method according to claim 1, wherein: a content of yttrium
oxide in the film is 99 mass % or more; a content of aluminum in
the film is 100 mass ppm or less; a content of magnesium in the
film is 20 mass ppm or less; a content of sodium in the film is 50
mass ppm or less; a content of zinc in the film is 100 mass ppm or
less; a content of calcium in the film is 100 mass ppm or less; a
content of potassium in the film is 5 mass ppm or less; and a
content of nickel in the film is 10 mass ppm or less.
8. The method according to claim 1, wherein a tensile strength B of
the film obtained after performing three cycles of exposing the
component to a temperature environment between 400.degree. C. and
600.degree. C. for 30 minutes and then exposing the component to a
temperature environment of 25.degree. C. for 30 minutes, with
respect to a tensile strength A of the film under a temperature
environment of 25.degree. C., satisfies an expression:
((A-B)/A).times.100%.ltoreq.20%.
9. The method according to claim 1, wherein the X-ray diffraction
pattern does not have a peak attributed to yttrium oxide whose
crystal structure is different from a crystal structure of the
cubic yttrium oxide, a thickness of the film is 100 .mu.m or less,
and in an observation image obtained by observing a cross section
in a thickness direction of the film by using a scanning electron
microscope at 10000 magnifications, a pore is not present or a
maximum diameter of a pore is 10 nm or less.
10. The method according to claim 1, wherein the X-ray diffraction
pattern does not have a peak attributed to yttrium oxide whose
crystal structure is different from a crystal structure of the
cubic yttrium oxide, a thickness of the film is 100 .mu.m or less,
in an observation image obtained by observing a cross section in a
thickness direction of the film by using a scanning electron
microscope at 10000 magnifications, a pore is not present or a
maximum diameter of a pore is 10 nm or less, a content of yttrium
oxide in the film is 99 mass % or more, a content of aluminum in
the film is 100 mass ppm or less, a content of magnesium in the
film is 20 mass ppm or less, a content of sodium in the film is 50
mass ppm or less, a content of zinc in the film is 100 mass ppm or
less, a content of calcium in the film is 100 mass ppm or less, a
content of potassium in the film is 5 mass ppm or less, and a
content of nickel in the film is 10 mass ppm or less.
Description
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application is a divisional application of U.S.
application Ser. No. 16/777,371 which is the continuation of
International Application No. PCT/JP2018/028376, filed on Jul. 30,
2018, which claims the benefit of priority from the prior Japanese
Patent Application No. 2017-147757, filed on Jul. 31, 2017; the
entire contents of which are incorporated herein by reference.
FIELD
[0002] Embodiments of the present invention relate to a component
and a semiconductor manufacturing apparatus.
BACKGROUND
[0003] A semiconductor element is manufactured by combining a
film-forming process and an etching process in a complicated
manner.
[0004] In recent years, a semiconductor element sometimes requires
fine wiring in accordance with high performance. A film-forming
process is carried out by, for example, a chemical vapor deposition
(CVD) method, a physical vapor deposition (PVD) method, or the
like. Further, the film-forming process is carried out by using
sputtering, an atomic layer deposition (ALD) method, or the like.
These methods utilize a vacuum. For example, in the sputtering,
ions are made to collide with a sputtering target, to thereby make
atoms sputtered from a target surface to be deposited on a base
material.
[0005] Dry etching is one kind of plasma etching. In the plasma
etching, a fluorine-based gas or a chlorine-based gas is subjected
to plasma discharge, to thereby generate fluorine-based plasma or
chlorine-based plasma. This makes it possible to perform etching on
a thin film on a base material. Further, there is also a method in
which an etching gas is turned into plasma, and sputtering with the
use of ions and a chemical reaction of the etching gas are
simultaneously performed, as in reactive ion etching (ME). By
employing the ME, it is possible to realize etching with high
accuracy and suitable for microfabrication.
[0006] As described above, the plasma processing is used in both
the film-forming process and the etching process. Accordingly, an
inside of a semiconductor manufacturing apparatus is exposed to
plasma. For this reason, a component mounted in the semiconductor
manufacturing apparatus is required to have resistance with respect
to the plasma (plasma resistance).
[0007] In order to improve yields of a semiconductor element, it is
required to further suppress particles. In particular, because of
realization of fine wiring, it is required to suppress generation
of particles whose average diameter is 0.1 .mu.m or less. It is
difficult to suppress the above-described particles of a
conventional yttrium oxide film.
[0008] A problem to be solved by an embodiment of the present
invention is to increase plasma resistance of a component.
BRIEF DESCRIPTION OF THE DRAWINGS
[0009] FIG. 1 is a view illustrating a configuration example of a
component.
[0010] FIG. 2 is a view illustrating an example of a
cross-sectional structure of a film.
[0011] FIG. 3 is a view illustrating a configuration example of a
semiconductor manufacturing apparatus.
DETAILED DESCRIPTION
[0012] A component of an embodiment includes a film containing
polycrystalline yttrium oxide. In an X-ray diffraction pattern of
the film, a ratio of a maximum intensity I.sub.m of a peak
attributed to monoclinic yttrium oxide to a maximum intensity
I.sub.c of a peak attributed to cubic yttrium oxide satisfies an
expression: 0.ltoreq.I.sub.m/I.sub.c.ltoreq.0.002.
[0013] Hereinafter, embodiments will be described with reference to
the drawings. Note that in the respective embodiments,
substantially the same components are denoted by the same reference
signs, and a part of description thereof may be omitted in some
cases. The drawings are schematic, and the relation between
thicknesses of respective parts and plane dimensions, ratios
between the thicknesses of the respective parts and the like may
differ from actual ones in some cases.
[0014] FIG. 1 is a view illustrating one example of a component. A
component 1 includes a film 2. The film 2 is provided on a base
material 3, for example. The film 2 contains polycrystalline
yttrium oxide. The polycrystalline yttrium oxide is mainly formed
of yttrium oxide crystals.
[0015] In an XRD diffraction pattern obtained by analyzing the film
2 by using an X-ray diffraction (XRD), a maximum intensity I.sub.m
of a peak attributed to monoclinic yttrium oxide with respect to a
maximum intensity I.sub.c of a peak attributed to cubic yttrium
oxide satisfies an expression:
0.ltoreq.I.sub.m/I.sub.c.ltoreq.0.002. The cubic yttrium oxide has
a crystal structure of cubic system. The monoclinic yttrium oxide
has a crystal structure of monoclinic system.
[0016] The peak attributed to the monoclinic yttrium oxide is
detected at a diffraction angle (2.theta.) of 30 degrees or more
and 33 degrees or less. Further, the peak attributed to the cubic
yttrium oxide is detected at a diffraction angle (2.theta.) of 28
degrees or more and 30 degrees or less. When the XRD diffraction
pattern has a plurality of peaks attributed to the monoclinic
yttrium oxide, the maximum intensity of the peak having the maximum
intensity out of the plurality of peaks, is defined as the maximum
intensity I.sub.m. Further, when the XRD diffraction pattern has a
plurality of peaks attributed to the cubic yttrium oxide, the
maximum intensity of the peak having the maximum intensity out of
the plurality of peaks, is defined as the maximum intensity
I.sub.c. When the film 2 is thin and is influenced by the base
material 3, it is also possible to measure the maximum intensities
I.sub.m, I.sub.c based on a thin film method.
[0017] The XRD analysis is performed by irradiating a surface of
the film 2 with X-rays. The XRD analysis is performed by using a Cu
target, at a tube voltage of 40 kV, at a tube current of 40 mA,
with a slit diameter (RS) of 0.15 mm, and at a scanning speed of
0.5 sec/STEP.
[0018] The yttrium oxide has a crystal structure of cubic system,
monoclinic system, or hexagonal system. A phase transition of the
yttrium oxide from a cubic crystal to a monoclinic crystal occurs
at a temperature in the vicinity of 1800.degree. C. A phase
transition of the yttrium oxide from a monoclinic crystal to a
hexagonal crystal occurs at a temperature in the vicinity of
2200.degree. C. The cubic crystal is stabilized at a temperature of
400.degree. C. or more and 1000.degree. C. or less.
[0019] A plasma processing process in a manufacturing process of a
semiconductor element is generally performed at a temperature of
400.degree. C. or more and 600.degree. C. or less. The cubic
yttrium oxide is stabilized in these temperature regions, so that
it is possible to prevent generation of strains due to the phase
transition. The monoclinic yttrium oxide has a larger number of
lattice defects when compared to the cubic yttrium oxide. The
monoclinic yttrium oxide is selectively corroded when it is exposed
to a plasma atmosphere. This leads to generation of particles.
[0020] The component of the embodiment can greatly improve its
plasma resistance by increasing a proportion of the cubic yttrium
oxide in the film 2. It is preferable that the X-ray diffraction
pattern does not have a peak attributed to yttrium oxide whose
crystal structure is different from a crystal structure of the
cubic yttrium oxide. When the expression:
0.ltoreq.I.sub.m/I.sub.c.ltoreq.0.002 is satisfied, this indicates
that the film 2 is substantially formed of the cubic yttrium oxide.
Besides, when I.sub.m/I.sub.c=0 is satisfied, it is indicated that
the X-ray diffraction pattern does not have a peak attributed to
the monoclinic yttrium oxide. Specifically, it is indicated that
the film 2 is formed of the cubic yttrium oxide. When
I.sub.m/I.sub.c exceeds 0.002, this indicates that a proportion of
the monoclinic yttrium oxide is larger than a proportion of the
cubic yttrium oxide.
[0021] In the component having the polycrystalline yttrium oxide
film having a mixed structure of the cubic yttrium oxide and the
monoclinic yttrium oxide, a weight decrease rate due to plasma
etching is low, but, uniformity of the film is also low.
I.sub.m/I.sub.c in a conventional polycrystalline yttrium oxide
film is 0.005 or more and 0.1 or less. On the contrary,
I.sub.m/I.sub.c in the film 2 is 0 or more and 0.002 or less. This
indicates that the uniformity of the film 2 is higher than the
uniformity of the conventional polycrystalline yttrium oxide film.
By decreasing LA, it is possible to reduce generation of particles
with a diameter of 0.1 .mu.m or more and 0.3 .mu.m or less in the
film 2.
[0022] A thickness of the film 2 is preferably 100 .mu.m or less.
When the thickness exceeds 100 .mu.m, a further effect cannot be
obtained, and on the contrary, this may lead to increase in cost.
Note that although a lower limit of the thickness is not
particularly limited, it is preferably 2 .mu.m or more. If the
thickness is less than 2 .mu.m, there is a possibility that a
mechanical strength of the film 2 is lowered. For this reason, the
thickness of the film 2 is preferably 2 .mu.m or more and 100 .mu.m
or less, and more preferably 10 .mu.m or more and 50 .mu.m or
less.
[0023] An average grain diameter of the polycrystalline yttrium
oxide is preferably 10 nm or less. By setting the average grain
diameter to 10 nm or less, it is possible to reduce the size and
the number of pores in the film 2. The pore is formed at a grain
boundary between crystals. The average grain diameter is preferably
10 nm or less, more preferably 1 nm or less, and still more
preferably 0.5 nm or less.
[0024] The average grain diameter can be measured by the following
measuring method, for example. A scanning electron microscope (SEM)
is used to take a macrophotograph of a surface of the film 2. The
number of pieces of yttrium oxide crystals that exist on a straight
line with a length of 5 .mu.m in the macrophotograph, is defined as
the average grain diameter.
[0025] FIG. 2 is a view illustrating one example of a
cross-sectional structure of the film 2. The film 2 has yttrium
oxide crystals 4. In an observation image obtained by observing an
arbitrary cross section in a thickness direction of the film 2 by
using the SEM at 10000 magnifications, a maximum diameter of a pore
is preferably 0 nm or more and 10 nm or less. The pore is observed
by performing ion milling processing on the arbitrary cross
section.
[0026] A longest diagonal line of a pore photographed in the SEM
photograph is set to the maximum diameter of the pore. When the
maximum diameter of the pore is 0 nm, this indicates a state where
the pore is not observed. When the maximum diameter of the pore is
reduced to 10 nm or less, there is no pore to be a cause of defect,
so that it is possible to improve the plasma resistance of the film
2. By reducing the average grain diameter of the polycrystalline
yttrium oxide (plural yttrium oxide crystals 4), it is possible to
set the maximum diameter of the pore in the film 2 to 10 nm or
less. Note that when the maximum diameter of the pore is 0 nm, this
indicates that the pore is not observed. When the SEM photograph is
used, it is possible to distinguish the pore from the yttrium oxide
crystal based on a difference in contrast.
[0027] A content of the yttrium oxide in the film 2 is preferably
99.0 mass % or more, and more preferably 99.3 mass % or more. A
content of impurity metal components in the film 2 is preferably 1
mass % or less, and more preferably 0.7 mass % or less. In
particular, it is preferable that a content of Al (aluminum) is 100
mass ppm or less, a content of Mg (magnesium) is 20 mass ppm or
less, a content of Na (sodium) is 50 mass ppm or less, a content of
Fe (iron) is 50 mass ppm or less, a content of Zn (zinc) is 100
mass ppm or less, a content of Ca (calcium) is 100 mass ppm or
less, a content of K (potassium) is 5 mass ppm or less, a content
of Ni (nickel) is 10 mass ppm or less, and a content of Cu (copper)
is 10 mass ppm or less. Further, each of these contents is a value
converted by a metal simple substance.
[0028] When Na, K, Ca, Mg are mixed in a semiconductor film, an
adverse effect is exerted on a semiconductor performance.
Accordingly, if Na or the like is mixed as an impurity when a
semiconductor element is manufactured by using a semiconductor
manufacturing apparatus including the aforementioned component, an
adverse effect is exerted on a performance of the semiconductor
element.
[0029] Al, Mg, Fe, Zn, Ni, Cu have a high reactivity with plasma.
For this reason, when the contents thereof exceed the
aforementioned contents, this becomes a cause of reducing the
plasma resistance. When a variation in refractive index is 1% or
less, this indicates that a dispersion state of the impurity metal
components is homogeneous. This makes it possible to prevent a
portion with low plasma resistance from being partially generated.
In other words, even in a case of containing a small amount of
impurity metal components, the plasma resistance can be improved by
making the dispersion state to be homogeneous.
[0030] A heat shock resistance of the component 1 can also be
improved by the film 2. The heat shock resistance can be judged by
a heat shock test of measuring a decreasing rate of a tensile
strength after exposure under a high-temperature environment with
respect to a tensile strength at an ordinary temperature
(25.degree. C.).
[0031] A decreasing rate X of a tensile strength B (MPa) after
exposure under a high-temperature environment with respect to a
tensile strength A (MPa) at an ordinary temperature is expressed by
an expression: X (%)=((A-B)/A).times.100.
[0032] In the processing of making the component 1 to be exposed
under the high-temperature environment, "30 minutes at 400.degree.
C..fwdarw.30 minutes at ordinary temperature" is set to processing
of one time (one cycle), and a tensile strength after repeating the
aforementioned processing three times (after three cycles) is set
to the tensile strength B. Since the component 1 is excellent in
the heat shock resistance, the decreasing rate of the tensile
strength can be set to 20% or less, further, it can be set to 15%
or less, and furthermore, it can be set to 10% or less. The tensile
strength is measured by, for example, a Sebastian tensile testing
method. Specifically, a test terminal is bonded to a surface of the
film 2 by using an epoxy adhesive, and then the test terminal is
pulled in a direction perpendicular to the surface of the film 2,
thereby determining a peel strength between the film 2 and a base
material 3.
[0033] As a Sebastian tensile tester, it is possible to use
Sebastian V-A model manufactured by Quad Group Inc., for example.
Test conditions are set such that FORCE LIMIT is set to "Max", an
Auto-side switch RATE is set to "one scale from LO (load adaptive
rate of 0.5 kg/sec to 10 kg/sec)", and SCALING is set to "FORCE".
Note that a tensile speed is changed depending on a tensile
strength, so that the load adaptive rate is 0.5 kg/sec to 10
kg/sec. The load adaptive rate becomes slow when the tensile
strength is high, and the load adaptive rate becomes fast when the
tensile strength is low.
[0034] Although 400.degree. C. is exemplified as the
high-temperature side, it is also possible to employ 600.degree. C.
The temperature range from 400.degree. C. to 600.degree. C. is a
temperature adjusted by assuming a maximum attained temperature in
a dry etching apparatus. Even after the component 1 is exposed
under a high-temperature environment of 600.degree. C., the
decreasing rate of the tensile strength can be set to 20% or less,
further, it can be set to 15% or less, and furthermore, it can be
set to 10% or less.
[0035] Next, a manufacturing method of the component 1 will be
described. Although the manufacturing method of the component 1 is
not particularly limited, the following method can be cited as a
method of obtaining the component 1 with good yields.
[0036] The base material 3 is prepared. As the base material 3,
there can be cited ceramics, a metal, or the like, for example,
but, it is not limited in particular. As the ceramics, there can be
cited aluminum oxide, aluminum nitride, or the like, for example.
As the metal, there can be cited copper, aluminum, stainless steel,
or the like, for example. A surface of the base material 3
preferably has a flat surface with a surface roughness Ra of 2
.mu.m or less.
[0037] Next, a process of forming a yttrium oxide film on the base
material 3 is performed. A film-forming method is preferably
sputtering. First, a sputtering target made of metal yttrium is
prepared. When the metal yttrium target is used, it is possible to
improve purity and density by repeating a melting method. For
example, in a target obtained by solidifying Y.sub.2O.sub.3
powders, it is difficult to realize densification. Further, since
there is a need to use a sintering aid for the densification,
mixing of impurities is unavoidable.
[0038] The purity of the metal yttrium target is preferably 99.0
mass % or more, and more preferably 99.3 mass % or more. It is
preferable that in the target, a content of Al (aluminum) is 300
mass ppm or less, a content of Mg (magnesium) is 20 mass ppm or
less, a content of Na (sodium) is 100 mass ppm or less, a content
of Fe (iron) is 50 mass ppm or less, a content of Zn (zinc) is 100
mass ppm or less, a content of Ca (calcium) is 100 mass ppm or
less, a content of K (potassium) is 10 mass ppm or less, a content
of Ni (nickel) is 20 mass ppm or less, and a content of Cu (copper)
is 20 mass ppm or less.
[0039] The content of metal yttrium excluding impurity rare-earth
elements is preferably 99.9 mass % or more. The impurity rare-earth
elements are rare-earth elements except for yttrium. By previously
controlling the amounts of the impurity metal components in the
metal yttrium target, it is possible to control the amounts of the
impurity metal components in the yttrium oxide film.
[0040] By performing sputtering on the metal yttrium target, a
metal yttrium film is formed. Next, an oxidation process is
performed. The formation of the metal yttrium film and the
oxidation process are alternately performed, to thereby form the
film 2. In the oxidation process, the metal yttrium film is heated
in an oxygen-containing atmosphere. By performing the heating in
the oxygen environment at a temperature of 1000.degree. C. or less,
the expression: 0.ltoreq.I.sub.m/I.sub.c.ltoreq.0.002 can be
satisfied.
[0041] When the oxidation is performed by setting a thickness of a
sputtering film that uses the metal yttrium target to 10 nm or
less, it is possible to set the average grain diameter of the
polycrystalline yttrium oxide crystals to 10 nm or less. When the
oxidation is performed by reducing the thickness of the sputtering
film, it is possible to reduce the size of the yttrium oxide
crystal. When the metal yttrium film formation, the oxidation
process, the metal yttrium film formation, and the oxidation
process are repeated, it is possible to form the polycrystalline
yttrium oxide in which the size and the number of pores are small.
Further, by employing the process of oxidizing the thin metal
yttrium film with the thickness of 10 nm or less, it is possible to
form a homogeneous film.
[0042] A film-forming atmosphere is preferably set to a vacuum
atmosphere. A degree of vacuum is preferably 0.5 Pa or less. The
oxidation process is preferably performed by using plasma
processing. The oxidation process is a process in which heat
treatment is performed in an oxygen-containing atmosphere, to
thereby turn metal yttrium into yttrium oxide. As described above,
the metal yttrium film is a thin film of 10 nm or less. By using
the plasma processing, it is possible to perform the oxidation
process in a short period of time.
[0043] The plasma processing is preferably performed for one second
or less per one process (1 sec/pass or less), and more preferably
performed at 0.5 sec/pass or less. It takes about 30 sec/pass in
normal heat treatment in an oxygen-containing atmosphere. By
performing the oxidation process in a short period of time, the
growth of crystal grain diameter can be suppressed. Further, by
performing the heat treatment in a vacuum, the way of transferring
heat to the metal yttrium film can be uniformized. When the way of
transferring heat is uniformized, the degree of grain growth
becomes uniform. Consequently, it is possible to suppress the
formation of pores.
[0044] It is also effective to employ reactive sputtering in which
a metal yttrium target is used and sputtering is performed in an
oxygen-containing atmosphere. The reactive sputtering is a method
of forming a yttrium oxide film while making the target react with
oxygen in the sputtering atmosphere. Since the method has no
oxidation heat treatment process when compared to the
above-described method of oxidizing the metal yttrium film, a load
on a manufacturing facility is reduced. Meanwhile, since the target
is made to react with oxygen in the sputtering atmosphere, a
film-forming time is long. In the above-described manufacturing
method, the film formation by using the Y.sub.2O.sub.3 powders with
the use of combustion flame is not performed, so that the
monoclinic yttrium oxide is difficult to be formed.
[0045] When the yttrium oxide film is formed by using the
combustion flame, the Y.sub.2O.sub.3 powders are instantly exposed
to a high temperature, so that the monoclinic yttrium oxide is
likely to be formed. On the contrary, the film 2 is formed by
oxidizing the metal yttrium film, for example, so that it is
possible to form a film having the polycrystalline yttrium oxide
substantially formed only of the cubic yttrium oxide.
[0046] Next, an example of a semiconductor manufacturing apparatus
including the component of the embodiment will be described. An
example of a semiconductor manufacturing apparatus of an embodiment
includes a chamber, a support provided in the chamber and on which
a base material is mounted, and a mechanism for generating plasma
in the chamber to perform plasma processing. The above-described
mechanism has the component of the embodiment.
[0047] As the plasma processing, there can be cited RIE, plasma
CVD, ALD, PVD, sputtering, plasma etching, or the like.
[0048] A manufacturing process of a semiconductor element often
employs a process using CVD, PVD, or the like, and performed by
using plasma. A wiring film is etched to form fine wiring. For
example, an etching process uses a dry etching method. The dry
etching is one kind of plasma etching. In a plasma etching method,
a fluorine-based gas or a chlorine-based gas is subjected to plasma
discharge, to thereby generate fluorine-based plasma or
chlorine-based plasma. Consequently, it is possible to perform
etching on a thin film on a base material.
[0049] In the RIE, an etching gas is turned into plasma, and
sputtering with the use of ions and a chemical reaction of the
etching gas are simultaneously performed. By employing the RIE, it
is possible to realize etching with high accuracy and suitable for
microfabrication.
[0050] The inside of the semiconductor manufacturing apparatus is
exposed to plasma. By improving the plasma resistance of a
component used in the semiconductor manufacturing apparatus, it is
possible to improve the durability of the apparatus itself.
Further, since the generation of particles can also be prevented,
the yields of the semiconductor element can also be improved.
[0051] As the component, there can be cited, for example, an
electrostatic chuck, a chamber, a microwave introducing window, a
shower head, a focus ring, a shield ring, or the like. Further, the
use of the component is effective in a manufacturing apparatus of a
semiconductor element required to have finer wiring, such as CMOS
(Complementary Metal Oxide Semiconductor).
[0052] FIG. 3 is a schematic view illustrating a configuration
example of a dry etching apparatus as a semiconductor manufacturing
apparatus. A semiconductor manufacturing apparatus illustrated in
FIG. 3 includes a processing chamber 40, a discharge tube 41, a
sample stage 44, a waveguide 46, a solenoid coil 47 generating a
magnetic field in the discharge tube 41, and a magnetron 48
provided to an end portion of the waveguide 46 and generating a
microwave.
[0053] The processing chamber 40 has a space for performing the
plasma processing, a gas supply port 42 for introducing an etching
gas, and a vacuum exhaust port 43. The vacuum exhaust port 43 is
connected to a vacuum pump, for example. The vacuum pump exhausts
air in the processing chamber 40 to form a vacuum atmosphere.
[0054] The discharge tube 41 is provided at an upper part of the
processing chamber 40. The discharge tube 41 is formed of quartz or
the like, for example. The component of the embodiment is used for
the discharge tube 41, for example. When the discharge tube 41 is
the base material 3, the film 2 is provided to an inner surface of
the discharge tube 41. On the outside of the discharge tube 41, the
waveguide 46 is provided.
[0055] The sample stage 44 is provided inside the processing
chamber 40. The sample stage 44 is connected to a high-frequency
power source 45, and can receive a high-frequency power.
[0056] In the semiconductor manufacturing apparatus illustrated in
FIG. 3, an etching gas is introduced from the gas supply port 42
into the inside of the processing chamber 40, and the air in the
processing chamber 40 is exhausted under reduced pressure. The
microwave from the magnetron 48 is introduced into the inside of
the discharge tube 41 by the waveguide 46, and the magnetic field
is formed by the solenoid coil 47. By an interaction of an electric
field of the microwave and the magnetic field formed by the
solenoid coil 47, the etching gas in the discharge tube 41 is
turned into plasma. Besides, the high-frequency power is applied to
the sample stage 44 by the high-frequency power source 45 to
generate a bias voltage, and ions in the plasma are drawn toward a
wafer 49 side to perform anisotropic etching.
[0057] The component of the embodiment has high plasma resistance.
Accordingly, when the component is used in the semiconductor
manufacturing apparatus, it is possible to reduce the generation of
particles. Further, since it is possible to suppress exposure of a
surface of the discharge tube 41, it is possible to reduce the
generation of particles due to peeling of a part of the
surface.
EXAMPLES
Examples 1 to 5, Comparative Example 1
[0058] As a base material, an alumina substrate was prepared.
Polishing was performed so that a surface roughness Ra of a surface
of the substrate became 1.0 .mu.m. Next, a metal yttrium target
with purity of 99.5 mass % was prepared. On the alumina substrate,
a process of forming a metal yttrium film and an oxidation process
were repeatedly performed to form a film containing polycrystalline
yttrium oxide. Further, in each of Examples 1 to 3, a thickness of
the metal yttrium film was set to fall within a range of 3 to 7 nm.
By repeatedly performing the metal yttrium film formation process
and the oxidation process, components 1 each having a thickness
shown in Table 1 were produced.
[0059] In Example 5, the component was produced by repeatedly
performing the formation of the metal yttrium film with a thickness
of 80 to 100 nm and the oxidation process. A thickness of a yttrium
oxide film in each of Examples and Comparative Example was unified
to 20 .mu.m. In Examples 1, 2, plasma processing was used to
perform an oxidation process at 0.5 sec/pass or less. In Example 3
and Example 5, heat treatment was performed at an average rate of
30 sec/pass in an oxygen-containing atmosphere. In Example 4, film
formation was performed based on a reactive sputtering method in an
oxygen-containing atmosphere. In Comparative Example 1, a
Y.sub.2O.sub.3 film was formed based a conventional method of using
combustion flame.
[0060] In the metal yttrium target, a content of Al (aluminum) is
100 mass ppm or less, a content of Mg (magnesium) is 5 mass ppm or
less, a content of Na (sodium) is 10 mass ppm or less, a content of
Fe (iron) is 20 mass ppm or less, a content of Zn (zinc) is 10 mass
ppm or less, a content of Ca (calcium) is 10 mass ppm or less, a
content of K (potassium) is 5 mass ppm or less, a content of Ni
(nickel) is 10 mass ppm or less, and a content of Cu (copper) is 10
mass ppm or less. When impurity rare-earth elements are included in
impurity metals, the purity of the metal yttrium target was 99.2
mass %.
[0061] The components according to Examples and Comparative Example
were subjected to XRD analysis. The XRD analysis was performed by
using a Cu target, at a tube voltage of 40 kV, at a tube current of
40 mA, with a slit diameter (RS) of 0.15 mm, and at a scanning
speed of 0.5 sec/STEP. I.sub.m/I.sub.c was determined by setting a
peak appeared at a diffraction angle (2.theta.) of 30 degrees or
more and 33 degrees or less to a peak attributed to a monoclinic
crystal, and setting a peak appeared at a diffraction angle
(2.theta.) of 28 degrees or more and 30 degrees or less to a peak
attributed to a cubic crystal.
[0062] An average grain diameter of polycrystalline yttrium oxide
was determined. The average grain diameter was determined based on
a linear density method of observing a film surface with a SEM and
determining the number of yttrium oxide crystals on a straight line
of 5 .mu.m.
[0063] A maximum diameter of a pore in the film was determined. In
an observation image obtained by observing a cross section of the
film by using the SEM at 10000 magnifications, a longest diagonal
line of a pore was set to the maximum diameter of the pore. A major
axis of the largest pore within a range of unit area of 5
.mu.m.times.5 .mu.m in an arbitrary cross section was indicated as
the maximum diameter. Results thereof are shown in Table 1.
TABLE-US-00001 TABLE 1 Film Thickness Average grain Maximum
diameter (.mu.m) I.sub.m/I.sub.c diameter (nm) of pore (nm) Example
1 20 0 0.2 0 Example 2 20 0 0.5 2 Example 3 20 0.001 1.5 3 Example
4 20 0.001 3.8 5 Example 5 20 0.002 89 15 Comparative 20 0.1 1.6 4
Example 1
[0064] As can be understood from Table, I.sub.m/I.sub.c of the film
according to each of Examples 1 to 5 was 0.002 or less. Further, in
each of Example 1 and Example 2 in which I.sub.m/I.sub.c was 0, a
peak attributed to the monoclinic yttrium oxide was not detected,
and only peaks attributed to the cubic yttrium oxide were detected.
Further, in Example 1, no pore was observed in the unit area of 5
.mu.m.times.5 .mu.m. Note that the fact that the X-ray diffraction
pattern indicates only the peaks attributed to the cubic crystals,
can be confirmed by comparison with 00-041-1105 or 00-043-1036 of
PDF database.
[0065] In Example 5, the average grain diameter was large to be 89
nm. In accordance with the increase in size of the grain diameter,
the maximum diameter of the pore was also large. In Comparative
Example 1, I.sub.m/I.sub.c was large to be 0.1.
[0066] Next, the heat shock resistance of the components according
to Examples and Comparative Example was measured. The heat shock
resistance was determined based on a decreasing rate of a tensile
strength B with respect to a tensile strength A. The measurement
under high-temperature environments was conducted at 400.degree. C.
and at 600.degree. C. Concretely, "30 minutes at 400.degree.
C..fwdarw.30 minutes at ordinary temperature" was set to one cycle,
and the tensile strength B after three cycles was measured.
Further, "30 minutes at 600.degree. C..fwdarw.30 minutes at
ordinary temperature" was set to one cycle, and the tensile
strength B after three cycles was measured. The tensile strength
was measured by the Sebastian tensile testing method. Concretely, a
test terminal was bonded to a surface of the film by using an epoxy
adhesive, and then the test terminal was pulled in a direction
perpendicular to the surface of the film, thereby determining a
peel strength between the base material and the film. The
measurement was performed five times for each of the tensile
strength A and the tensile strength B, and results thereof were
indicated by minimum values and maximum values. Further, average
values of five times of the measurements were also indicated.
Further, as the decreasing rate, the lowest rate was described.
[0067] As a Sebastian tensile tester, Sebastian V-A model
manufactured by Quad Group Inc. was used. Test conditions were set
such that FORCE LIMIT was set to "Max", an Auto-side switch RATE
was set to "one scale from LO (load adaptive rate of 0.5 kg/sec to
10 kg/sec)", and SCALING was set to "FORCE". Results thereof are
shown in Table 2.
TABLE-US-00002 TABLE 2 Tensile strength A (MPa) Tensile strength B
Ordinary (MPa) temperature 400.degree. C. 600.degree. C. Min. Max.
Ave. Min. Max. Ave. Decreasing Min. Max. Ave. Decreasing value
value value value value value rate (%) value value value rate (%)
Ex.1 22 60 74 60 78 72 5% or 59 75 71 6% or less less Ex. 2 60 75
70 57 72 68 5% or 55 69 67 6% or less less Ex. 3 55 70 65 50 66 62
7% or 46 62 59 8% or less less Ex. 4 65 75 68 58 68 62 7% or 52 64
60 9% or less less Ex. 5 52 57 53 40 47 44 15% or 37 44 42 17% or
less less Comparative 25 40 32 10 30 21 30% or 5 20 18 30% or Ex. 1
more more
[0068] In each of Examples 1 to 4, the decreasing rate of the
tensile strength was 10% or less. Further, in Example 5, the
decreasing rate was 17% or less at 600.degree. C. This is because
the average grain diameter of the polycrystalline yttrium oxide was
large to be 89 nm. On the contrary, in Comparative Example 1, the
decreasing rate was deteriorated to be 30% or more.
[0069] The minimum value of the tensile strength A was 52 MPa or
more, the maximum value of the tensile strength A was 57 MPa or
more, the average value of the tensile strength A was 53 MPa or
more, the minimum value of the tensile strength B was 37 MPa or
more, the maximum value of the tensile strength B was 44 MPa or
more, and the average value of the tensile strength B was 42 MPa or
more.
[0070] Next, the plasma resistance of the components according to
Examples and Comparative Example was examined. As the plasma
resistance, both a fluorine-based gas and a chlorine-based gas used
in a plasma etching process were used to examine a weight decrease
amount and the presence/absence of generation of particles.
Further, the examination was performed also on the components whose
thicknesses were respectively changed.
[0071] As the weight decrease amount, a weight reduced after 24
hours of the performance of the plasma etching process was
indicated as the weight decrease amount. Further, the number of
pieces of generated particles on a Si substrate was indicated while
classifying sizes of the particles into a size of less than 0.1
.mu.m and a size of 0.1 .mu.m or more. Note that the number of
pieces of generated particles was set to the number of pieces per
unit area of 1 cm.sup.2 on the Si substrate. Results thereof are
shown in Table 3.
TABLE-US-00003 TABLE 3 Weight decrease amount Particle Thick-
(mg/cm.sup.2) (Pieces/cm.sup.2) ness Flourine- Chlorine- Less than
0.1 .mu.m (.mu.m) based gas based gas 0.1 .mu.m or more Ex. 1 20
0.003 0.003 8 3 10 0.003 0.003 8 3 Ex. 2 20 0.008 0.008 9 4 30
0.008 0.008 9 4 Ex. 3 20 0.014 0.016 11 6 50 0.014 0.016 11 6 Ex. 4
20 0.035 0.032 16 10 80 0.037 0.035 16 10 Ex. 5 20 0.098 0.092 28
17 120 0.112 0.103 30 21 Comparative 20 0.143 0.156 78 46 Ex. 1
[0072] As can be understood from Table, in each of Examples in
which the proportion of cubic yttrium oxide was increased, the
weight decrease amount was reduced. It can be understood that the
plasma resistance is excellent. Further, in accordance with that,
the generation amount of particles was also reduced. In particular,
it is possible to reduce small particles with an average diameter
of less than 0.1 .mu.m. It is possible to sufficiently deal with
the realization of fine wiring.
[0073] When the average grain diameter and the maximum diameter of
pore were increased as in Example 5, the plasma resistance was
lowered. In particular, when the thickness exceeded 100 .mu.m, the
plasma resistance was lowered. For this reason, it was confirmed
that the thickness is preferably 100 .mu.m or less, and more
preferably 10 .mu.m or more and 50 .mu.m or less. When was out of
the range as in Comparative Example, the plasma resistance was
lowered.
[0074] While certain embodiments of the present invention have been
exemplified, these embodiments have been presented by way of
example only, and are not intended to limit the scope of the
inventions. Indeed, the novel embodiments described herein may be
embodied in a variety of other forms; furthermore, various
omissions, substitutions, changes, and the like in the form of the
embodiments described herein may be made without departing from the
spirit of the inventions. The accompanying claims and their
equivalents are intended to cover such forms or modification
examples as would fall within the scope and spirit of the
inventions. Further, the aforementioned respective embodiments can
be mutually combined to be carried out.
* * * * *