Patent US5110408A successfully refreshed from Google Patents.
US5110408A
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Process for etching
Assignee: Hitachi Ltd
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Filing: 1991-02-20
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Granted: 1992-05-05
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Expires: 2011-02-20
Abstract
Abstract The present invention relates to the etching of a gate film, a tungsten film, a silicon film, etc. In the present invention, use is made of an etching gas comprising a mixture composed of a reductive fluoride gas, a hydrocarbon gas and a halogen gas having a larger atomic diameter than a material to be etched, or a mixture composed of a reductive fluoride gas and a Cl-containing hydrocarbon gas, and the process comprises the step of conducting anisotropic etching of a material to be etched with an etching gas (a reductive fluoride gas), the step of forming a protective film by a depositing gas (a hydrocarbon gas), and the step of removing excess deposits formed as the protective film by means of a gas reactive with the protective film (a halogen gas or a Cl-containing hydrogen gas), wherein anisotropic etching is conducted by forming a protective film on a side wall while removing excess deposits formed as the protective film, thus enabling the anisotropic etching to be conducted with good accuracy.
Inventors
- 👤 Takashi Fujii
- 👤 Hironobu Kawahara
- 👤 Kazuo Takata
- 👤 Masaharu Nishiumi
- 👤 Noriaki Yamamoto
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-08 15:10
CPC Classifications
H; H10; H10P; H10P50/00; H10P50/20; H10P50/24; H10P50/242; H10P50/244; H10P50/26; H10P50/264; H10P50/266; H10P50/267; H10P50/268; H10P50/69; H10P50/691; H10P50/693; H10P50/694; H10P50/71
Claims Analysis
Total Claims: 30
Claim 1
Independent Claim
65 words
A process for etching which comprises etching at least one material selected from the group consisting of a polycrystal silicon film, a tungsten alloy film, a tungsten film and a silicon substrate by using, as an etching gas, a mixture comprising a reductive fluoride gas, a hydrocarbon gas and a halogen gas having a larger atomic diameter than that of the material to be etched.
Claim 2
Dependent Claim
65 words
A process for etching which comprises etching at least one material selected from the group consisting of a polycrystal silicon film, a tungsten alloy film, a tungsten film and a silicon substrate by using, as an etching gas, a mixture comprising a reductive fluoride gas, a hydrocarbon gas and a halogen gas having a larger atomic diameter than that of the material to be etched.
Claim 3
Dependent Claim
20 words
A process for etching according to claim 1, wherein said reductive fluoride gas is SF 6 or NF 3 .
Claim 4
Dependent Claim
60 words
A process for etching according to claim 1, wherein said hydrocarbon gas is CHF 3 , CH 2 F 2 , CH 3 F, C 2 H 2 F 2 , C 2 HF 2 , C 2 H 3 F, C 2 H 5 F, C 2 H 4 F 2 or C 2 H 3 F 3 .
Claim 5
Dependent Claim
23 words
A process for etching according to claim 1, wherein said halogen gas is Cl 2 , Br 2 , or I 2 .
Claim 6
Dependent Claim
41 words
A process for etching according to claim 1, wherein said at least one material is a WSi x /polycrystal silicon film or a polycrystal silicon film or a tungsten film, said etching being performed so as to form a gate film.
Claim 7
Dependent Claim
22 words
A process for etching according to claim 1, wherein said tungsten alloy film is a WSi x film or a TiW film.
Claim 8
Dependent Claim
40 words
A process for etching according to claim 1, wherein the etching is conducted by means of a microwave plasma through the application of a high-frequency power to a sample piece support on which the material to be etched is placed.
Claim 9
Dependent Claim
51 words
A process for etching which comprises etching at least one material selected from the group consisting of a polycrystal silicon film, a tungsten alloy film, a tungsten film and a silicon substrate by using a mixture composed of a reductive fluoride gas and a Cl-containing hydrocarbon gas as an etching gas.
Claim 10
Dependent Claim
51 words
A process for etching which comprises etching at least one material selected from the group consisting of a polycrystal silicon film, a tungsten alloy film, a tungsten film and a silicon substrate by using a mixture composed of a reductive fluoride gas and a Cl-containing hydrocarbon gas as an etching gas.
Claim 11
Dependent Claim
20 words
A process for etching according to claim 8, wherein said reductive fluoride gas is SF 6 or NF 3 .
Claim 12
Dependent Claim
29 words
A process for etching according to claim 8, wherein said Cl-containing hydrocarbon gas is CHClF 2 , CHCl 2 F, CH 3 Cl or CH 2 Cl 2 .
Claim 13
Dependent Claim
40 words
A process for etching according to claim 8, wherein said at least one material is a WSi x /polycrystal silicon film, a polycrystal silicon film or a tungsten film, said etching being performed so as to form a gate film.
Claim 14
Dependent Claim
22 words
A process for etching according to claim 8, wherein said tungsten alloy film is a WSi x film or a TiW film.
Claim 15
Dependent Claim
40 words
A process for etching according to claim 8, wherein the etching is conducted by means of a micro-wave plasma through the application of a high-frequency power to a sample piece support on which the material to be etched is placed.
Claim 16
Dependent Claim
64 words
A process for etching a material to be etched, using a gas plasma, which comprises the step of conducting, with an etching gas, anisotropic etching of the material to be etched, the step of forming a protective film by a depositing gas, and the step of removing excess deposits formed as the protective film by means of a gas reactive with the protective film.
Claim 17
Dependent Claim
64 words
A process for etching a material to be etched, using a gas plasma, which comprises the step of conducting, with an etching gas, anisotropic etching of the material to be etched, the step of forming a protective film by a depositing gas, and the step of removing excess deposits formed as the protective film by means of a gas reactive with the protective film.
Claim 18
Dependent Claim
17 words
A process for etching according to claim 14, wherein all of said steps are conducted at once.
Claim 19
Dependent Claim
22 words
A process for etching according to claim 14, wherein said material to be etched is a tungsten film or a silicon substrate.
Claim 20
Dependent Claim
49 words
A process for etching according to claim 14, wherein a reductive fluoride gas, a hydrocarbon gas and a halogen gas having a larger atomic diameter than the material to be etched are used respectively as said etching gas, said depositing gas and said gas reactive with the protective film.
Claim 21
Dependent Claim
39 words
A process for etching according to claim 14, wherein a reductive fluoride gas is used as said etching gas and a Cl-containing hydrocarbon gas is used as both said depositing gas and said gas reactive with the protective film.
Claim 22
Dependent Claim
40 words
A process for etching according to claim 14, wherein the etching is conducted by means of a micro-wave plasma through the application of a high-frequency power to a sample piece support on which the material to be etched is placed.
Claim 23
Dependent Claim
15 words
A process for etching according to claim 1, wherein the etching is an anisotropic etching.
Claim 24
Dependent Claim
41 words
A process for etching according to claim 1, wherein, during the etching, the halogen gas having a larger atomic diameter than the material to be etched removes a deposit formed on side and bottom walls of the material to be etched.
Claim 25
Dependent Claim
20 words
A process for etching according to claim 21, wherein said deposit is removed in the form of a chlorine compound.
Claim 26
Dependent Claim
56 words
A process for etching according to claim 7, wherein the sample piece support is provided in an etching chamber, a discharge tube forming a top of the etching chamber, and wherein during the etching the halogen gas having a larger atomic diameter than the material to be etched removes a deposit formed on the discharge tube.
Claim 27
Dependent Claim
47 words
A process for etching according to claim 14, wherein the material to be etched is a barrier metal of a multilayer interconnection of an integrated circuit, said anisotropic etching being performed so as to form a barrier layer of a laminate wiring structure of the multilayer interconnection.
Claim 28
Dependent Claim
20 words
A process for etching according to claim 14, wherein said etching is performed so as to form a gate film.
Claim 29
Dependent Claim
20 words
A process for etching according to claim 8, wherein said etching is performed so as to form a gate film.
Claim 30
Dependent Claim
20 words
A process for etching according to claim 1, wherein said etching is performed so as to form a gate film.
References Cited (Backward Citations)
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