US4529476A
Expired / Lapsed
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Gas for selectively etching silicon nitride and process for selectively etching silicon nitride with the gas
Assignee: Hitachi Ltd
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Filing: 1984-06-01
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Granted: 1985-07-16
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Expires: 2004-06-01
Abstract
Abstract A dry-etching gas suitable for selective etching of silicon nitride and a process for selectively dry-etching silicon nitride with the dry-etching gas are disclosed. Silicon nitride can be dry-etched with a higher selectivity or at a higher etching rate than silicon dioxide and silicon, and a process for fabricating semi-conductor devices can be simplified and devices with a novel structure can be realized.
Inventors
- 👤 Yoshifumi Kawamoto
- 👤 Hiroshi Kawakami
- 👤 Tokuo Kure
- 👤 Shinichi Tachi
- 👤 Norikazu Hashimoto
- 👤 Tsuyoshi Takaichi
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-29 08:22
CPC Classifications
C; C04; C04B; C04B41/00; C04B41/009; C04B41/53; C04B41/5338; C04B41/5346; C04B41/80; C04B41/91; C09; C09K; C09K13/00; C09K13/04; C09K13/08; H; H10; H10P; H10P50/00; H10P50/20; H10P50/28; H10P50/282; H10P50/283
Claims Analysis
Total Claims: 15
Claim 1
Independent Claim
34 words
A gas for selectively etching silicon nitride, which comprises a composition consisting of C, H and F atom species and having a ratio of F to H by atom of not more than 2.
Claim 2
Dependent Claim
34 words
A gas for selectively etching silicon nitride, which comprises a composition consisting of C, H and F atom species and having a ratio of F to H by atom of not more than 2.
Claim 3
Dependent Claim
18 words
A gas according to claim 1, wherein the gas has a carbon number of not more than 3.
Claim 4
Dependent Claim
89 words
A gas according to claim 1 or 2, wherein the gas is at least one member selected from the group consisting of CH 2 F 2 , CH 3 F, C 2 H 5 F, C 2 H 4 F 2 , C 2 H 3 F 3 , C 2 H 2 F 4 , C 3 H 7 F, C 3 H 6 F 2 , C 3 H 5 F 3 , C 3 H 4 F 4 and C 3 H 3 F 5 .
Claim 5
Dependent Claim
57 words
A process for etching an article by contact of the article with a plasma of a reacting gas, which comprises selectively etching silicon nitride as the article with a gas consisting of C, H and F atom species and having a ratio of F to H by atom of not more than 2 as the reacting gas.
Claim 6
Dependent Claim
57 words
A process for etching an article by contact of the article with a plasma of a reacting gas, which comprises selectively etching silicon nitride as the article with a gas consisting of C, H and F atom species and having a ratio of F to H by atom of not more than 2 as the reacting gas.
Claim 7
Dependent Claim
19 words
A process according to claim 4, wherein the reacting gas has a carbon number of not more than 3.
Claim 8
Dependent Claim
90 words
A process according to claim 4 or 5, wherein the reacting gas is at least one member selected from the group consisting of CH 2 F 2 , CH 3 F, C 2 H 5 F, C 2 H 4 F 2 , C 2 H 3 F 3 , C 2 H 2 F 4 , C 3 H 7 F, C 3 H 6 F 2 , C 3 H 5 F 3 , C 3 H 4 F 4 and C 3 H 3 F 5 .
Claim 9
Dependent Claim
23 words
A process according to claim 4, wherein the etching is carried out in a reactive sputter etching apparatus in a parallel plate type.
Claim 10
Dependent Claim
16 words
A process according to claim 7, wherein the reacting gas has a pressure of 0.01-0.1 Torr.
Claim 11
Dependent Claim
29 words
A process according to claim 4, wherein at least one of silicon dioxide film and polycrystalline silicon film, and a film of the silicon nitride are exposed to surface.
Claim 12
Dependent Claim
28 words
A process according to claim 9, where the film of the silicon nitride is etched by masking the silicon dioxide film or the polycrystalline silicon film or both.
Claim 13
Dependent Claim
28 words
A process according to claim 4, wherein the film of the silicon nitride is formed on a silicon substrate, the polycrystalline silicon film or the silicon dioxide film.
Claim 14
Dependent Claim
33 words
A process according to claim 4, wherein the reacting gas is mixed with at least one member selected from the group consisting of N 2 , O 2 , H 2 and He.
Claim 15
Dependent Claim
28 words
A process according to claim 4, wherein the reacting gas is a mixture of at least one of CF 4 and CHF 3 , and H 2 .
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1988-07-15 | 1989-01-14 | 1989-07-16 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1992-07-15 | 1993-01-14 | 1993-07-16 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1996-07-15 | 1997-01-14 | 1997-07-16 | $7700.00 | Window Closed / Lapsed |