Patent US5201994A successfully refreshed from Google Patents.
US5201994A
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US
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Dry etching method
Assignee: Shibaura Mechatronics Corp
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Filing: 1989-11-17
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Granted: 1993-04-13
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Expires: 2009-11-17
Abstract
Abstract The present invention relates to a dry etching method in which the type of reactive gas used is improved and the selectively between a workpiece being etched and a substance below the workpiece is increased. A gas comprising a fluoride gas and a compound gas containing hydrogen as a constituent element is used as the reactive gas. According to the present invention, the etching selectivity between a workpiece being etched and a substance below the workpiece is greatly increased, and etching of the substance below the workpiece can be prevented. The present invention is applicable to a semiconductor structure having a silicon oxide film below a silicon nitride film.
Inventors
- 👤 Mikio Nonaka
- 👤 Hiroyuki Hara
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-31 13:24
CPC Classifications
H; H10; H10P; H10P50/00; H10P50/20; H10P50/24; H10P50/242; H10P50/28; H10P50/282; H10P50/283; H10P50/26; H10P50/264; H10P50/266; H10P50/267; H10P50/268; H10P50/286; H10P50/287
Claims Analysis
Total Claims: 6
Claim 1
Independent Claim
54 words
A method of dry etching comprising the steps of: introducing reacting gas into a vacuum chamber, said reacting gas being a mixture of fluoride gas, oxygen and alcohol; applying a microwave electric field to generate a plasma; and injecting activated particles in said plasma to a workpiece to be etched in said vacuum chamber.
Claim 2
Independent Claim
54 words
A method of dry etching comprising the steps of: introducing reacting gas into a vacuum chamber, said reacting gas being a mixture of fluoride gas, oxygen and alcohol; applying a microwave electric field to generate a plasma; and injecting activated particles in said plasma to a workpiece to be etched in said vacuum chamber.
Claim 3
Dependent Claim
16 words
A method of dry etching as set forth in claim 1, wherein said alcohol is ethylalcohol.
Claim 4
Dependent Claim
16 words
A method of dry etching as set forth in claim 1, wherein said alcohol is methylalcohol.
Claim 5
Dependent Claim
19 words
A method of dry etching as set forth in claim 1, wherein said fluoride gas is CF 4 .
Claim 6
Dependent Claim
29 words
A method of dry etching as set forth in claim 2, wherein an additional amount of the ethylalcohol is selected from with the range of about 2% to 11%.
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) | 1996-04-12 | 1996-10-12 | 1997-04-13 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2000-04-12 | 2000-10-12 | 2001-04-13 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2004-04-12 | 2004-10-12 | 2005-04-13 | $7700.00 | Window Closed / Lapsed |