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US4595453A
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Method for etching a semiconductor substrate or layer
Assignee: Semiconductor Energy Laboratory Co Ltd
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Filing: 1984-09-24
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Granted: 1986-06-17
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Expires: 2004-09-24
Abstract
Abstract A semiconductor substrate or layer formed principally of silicon or silicon carbide is selectively or nonselectively etched by using a hydrogen fluoride gas plasma as a reactive gas plasma. In the case of nonselectively etching the semiconductor substrate or layer, a mask layer of silicon oxide, silicon nitride, metal such as aluminum, chrominum, nickel, cobalt, tantalum, tungsten or molybdenum, or photoresist is preformed into a required pattern on the semiconductor substrate or layer.
Inventors
- 👤 Shunpei Yamazaki
- 👤 Toshiji Hamatani
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 17:12
CPC Classifications
H; H10; H10P; H10P50/00; H10P50/69; H10P50/691; H10P50/692; H10P50/20; H10P50/24; H10P50/242
Claims Analysis
Total Claims: 8
Claim 1
Independent Claim
43 words
A method for etching a semiconductor substrate or layer formed principally of silicon or silicon carbide through the use of a reactive gas plasma, wherein said reactive gas plasma is a hydrogen fluoride gas plasma from which oxygen and oxides have been removed.
Claim 2
Independent Claim
43 words
A method for etching a semiconductor substrate or layer formed principally of silicon or silicon carbide through the use of a reactive gas plasma, wherein said reactive gas plasma is a hydrogen fluoride gas plasma from which oxygen and oxides have been removed.
Claim 3
Dependent Claim
20 words
A method according to claim 1, wherein said hydrogen fluoride gas plasma has a purity of more than 99 percent.
Claim 4
Dependent Claim
22 words
A method according to claim 1, wherein said etching is conducted at a pressure in the range of 0.05 to 3 Torr.
Claim 5
Independent Claim
101 words
A method for etching a semiconductor substrate or layer formed principally of silicon or silicon carbide into a required pattern through the use of a reactive gas plasma, said method comprising the steps of: forming on said semiconductor substrate or layer a mask layer of silicon oxide, silicon nitride, aluminum, chromium, nickel, cobalt, tantalum, tungsten or molydenum, or photoresist, said mask layer having an inverted pattern of said required pattern; and selectively etching away semiconductor substrate or layer through said mask layer using, as said reactive gas plasma, a hydrogen fluoride gas plasma from which oxygen and oxides have been removed.
Claim 6
Independent Claim
101 words
A method for etching a semiconductor substrate or layer formed principally of silicon or silicon carbide into a required pattern through the use of a reactive gas plasma, said method comprising the steps of: forming on said semiconductor substrate or layer a mask layer of silicon oxide, silicon nitride, aluminum, chromium, nickel, cobalt, tantalum, tungsten or molydenum, or photoresist, said mask layer having an inverted pattern of said required pattern; and selectively etching away semiconductor substrate or layer through said mask layer using, as said reactive gas plasma, a hydrogen fluoride gas plasma from which oxygen and oxides have been removed.
Claim 7
Dependent Claim
20 words
A method according to claim 4, wherein said hydrogen fluoride gas plasma has a purity of more than 99 percent.
Claim 8
Dependent Claim
19 words
A method according to claim 4, wherein said etching is conducted at a pressure of 0.05 to 3 Torr.
References Cited (Backward Citations)
US3615956A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1989-06-16 | 1989-12-16 | 1990-06-17 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1993-06-16 | 1993-12-16 | 1994-06-17 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1997-06-16 | 1997-12-16 | 1998-06-17 | $7700.00 | Window Closed / Lapsed |