US5223085A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Plasma etching method with enhanced anisotropic property and apparatus thereof
Assignee: Mitsubishi Electric Corp
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Filing: 1991-02-12
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Granted: 1993-06-29
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Expires: 2011-02-12
Abstract
Abstract A method for anisotropically etching a substrate to be treated using plasma of a reactive gas produced by electron cyclotron resonance is disclosed. A substrate to be treated is located in a processing container, and a chlorine gas and a hydrogen chloride gas are introduced into the processing container. From the mixture of the chlorine and hydrogen chloride gases introduced into the processing container, plasma of the mixed gas is produced by electron cyclotron resonance. According to this method, the energy of the plasma of chlorine is taken by the plasma of H + , which results in a decrease in kinetic energy of the chlorine. As a result, the plasma of chlorine impinges vertically to the substrate to be treated along the sheath electric field. Consequently, etching with strong anisotropic property is enabled.
Inventors
- 👤 Kenji Kawai
- 👤 Moriaki Akazawa
- 👤 Takahiro Maruyama
- 👤 Toshiaki Ogawa
- 👤 Hiroshi Morita
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-31 15:56
CPC Classifications
H; H10; H10P; H10P50/00; H10P50/20; H10P50/26; H10P50/264; H10P50/266; H10P50/267; H10P50/268; C; C23; C23F; C23F4/00
Claims Analysis
Total Claims: 10
Claim 1
Independent Claim
94 words
A method of etching a substrate interconnection layer of material selected from the group consisting of aluminum alloy, polysilicon, tungsten and tungsten silicide, comprising the steps of: locating said substrate into a processing container; introducing a gas mixture into said processing container, said gas mixture consisting of a halogen gas which is reactive and a light gas selected from the group consisting of hydrogen (H2) and hydrogen halide; forming a plasma of the gas mixture in said processing container by electron cyclotron resonance; and directing said plasma to said substrate interconnection layer for etching.
Claim 2
Independent Claim
94 words
A method of etching a substrate interconnection layer of material selected from the group consisting of aluminum alloy, polysilicon, tungsten and tungsten silicide, comprising the steps of: locating said substrate into a processing container; introducing a gas mixture into said processing container, said gas mixture consisting of a halogen gas which is reactive and a light gas selected from the group consisting of hydrogen (H2) and hydrogen halide; forming a plasma of the gas mixture in said processing container by electron cyclotron resonance; and directing said plasma to said substrate interconnection layer for etching.
Claim 3
Dependent Claim
14 words
The method according to claim 1, wherein said halogen gas comprises a chlorine gas.
Claim 4
Dependent Claim
26 words
The method according to claim 1, wherein said light gas comprises hydrogen halide selected from the group consisting of HF, HC l , HBr and HI.
Claim 5
Dependent Claim
65 words
The method according to claim 1, wherein the steps of forming plasma of said mixed gas by electron cyclotron resonance comprises the steps of: supplying microwave energy to said processing container in which said mixed gas is introduced; producing a magnetic field in said processing container in which said mixed gas is introduced; and exhausting a part of said mixed gas from said processing container.
Claim 6
Dependent Claim
31 words
The method according to claim 1, wherein said light gas is introduced into said processing container so that said light gas is included in said mixed gas by 20-70% in volume.
Claim 7
Dependent Claim
33 words
The method according to claim 5, wherein said light gas is introduced into said processing container so that the amount of said light gas in said mixed gas is approximately 50% in volume.
Claim 8
Dependent Claim
31 words
The method according to claim 1, wherein said reactive gas and said light gas are introduced into said processing container at flow rate of the entire mixed gas of 30-2000 SCCM.
Claim 9
Dependent Claim
23 words
The method according to claim 4, wherein said microwave energy is introduced into said processing container at a power of approximately 50-500 W.
Claim 10
Dependent Claim
24 words
The method according to claim 4, wherein said exhausting step is performed so that the vacuum of said processing container is approximately 0.1-1 Pa.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1996-06-28 | 1996-12-28 | 1997-06-29 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2000-06-28 | 2000-12-28 | 2001-06-29 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2004-06-28 | 2004-12-28 | 2005-06-29 | $7700.00 | Window Closed / Lapsed |