US4601778A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Maskless etching of polysilicon
Assignee: Motorola Solutions Inc
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Filing: 1985-02-25
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Granted: 1986-07-22
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Expires: 2005-02-25
Abstract
Abstract Maskless etching of polysilicon is accomplished by exposing portions of a polysilicon surface to ion bombardment. Bombardment by oxygen or hydrogen ions is effective to reduce the etch rate of polysilicon in a chlorine-containing plasma. Therefore, patterned ion bombardment prior to etching in a chlorine plasma is effective to pattern the polysilicon surface.
Inventors
- 👤 Francine Y. Robb
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-29 16:17
CPC Classifications
H; H10; H10P; H10P50/00; H10P50/20; H10P50/26; H10P50/264; H10P50/266; H10P50/267; H10P50/268; Y; Y10; Y10S; Y10S438/00; Y10S438/914; Y10S438/924
Claims Analysis
Total Claims: 3
Claim 1
Independent Claim
43 words
A method of etching polysilicon comprising the steps of: exposing a portion of a polysilicon film to at least one of an oxygen plasma and a hydrogen plasma; and exposing both treated and untreated portions of said polysilicon film to a polysilicon etchant.
Claim 2
Independent Claim
43 words
A method of etching polysilicon comprising the steps of: exposing a portion of a polysilicon film to at least one of an oxygen plasma and a hydrogen plasma; and exposing both treated and untreated portions of said polysilicon film to a polysilicon etchant.
Claim 3
Dependent Claim
15 words
A method according to claim 1 wherein said polysilicon etchant further comprises: a chlorine-containing plasma.
References Cited (Backward Citations)
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US4267011A
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US4377734A
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US4383885A
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US4438556A
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US4377437A
Cited
US4504574A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1989-07-21 | 1990-01-20 | 1990-07-22 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1993-07-21 | 1994-01-20 | 1994-07-22 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1997-07-21 | 1998-01-20 | 1998-07-22 | $7700.00 | Window Closed / Lapsed |