US4389294A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method for avoiding residue on a vertical walled mesa
Assignee: International Business Machines Corp
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Filing: 1981-06-30
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Granted: 1983-06-21
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Expires: 2001-06-30
Abstract
Abstract A method for eliminating deposited residues, for example polysilicon residue, on vertical silicon dioxide sidewalls that have been reactive ion etched includes reshaping the sidewalls to have a slope of at least +30° relative to the vertical direction of the sidewall.
Inventors
- 👤 Narasipur G. Anantha
- 👤 Harsaran S. Bhatia
- 👤 John L. Mauer, IV
- 👤 Homi G. Sarkary
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-29 16:46
CPC Classifications
H; H10; H10W; H10W10/00; H10W10/01; H10W10/011; H10W10/014; H10P; H10P50/00; H10P50/20; H10P50/28; H10P50/282; H10P50/283; H10P95/00; H10P95/06; H10P95/062; H10P95/064; H10W10/012; H10W10/10; H10W10/13; H10W10/17; Y; Y10; Y10S; Y10S438/00; Y10S438/978
Claims Analysis
Total Claims: 9
Claim 1
Independent Claim
77 words
A method for avoiding residue on a vertical walled dielectric mesa of a layer to be deposited on said mesa and to be removed by reactive ion etching comprising the steps of providing a silicon substrate having said dielectric mesa on a surface thereof, and reshaping a wall of said dielectric mesa so as to be sloping at an angle equal to or greater than 30° relative to a line vertical to said surface of said substrate.
Claim 2
Independent Claim
77 words
A method for avoiding residue on a vertical walled dielectric mesa of a layer to be deposited on said mesa and to be removed by reactive ion etching comprising the steps of providing a silicon substrate having said dielectric mesa on a surface thereof, and reshaping a wall of said dielectric mesa so as to be sloping at an angle equal to or greater than 30° relative to a line vertical to said surface of said substrate.
Claim 3
Dependent Claim
21 words
A method as described in claim 1 whereby the reshaping is accomplished by removing material from the wall of said mesa.
Claim 4
Dependent Claim
18 words
A method as described in claim 2 whereby the material is removed from the mesa by ion milling.
Claim 5
Independent Claim
90 words
A method for avoiding residue on a vertical walled dielectric mesa of a layer to be deposited on said mesa and to be removed by reactive ion etching comprising the steps of providing a silicon substrate having said dielectric mesa on a surface thereof, reshaping a wall of said mesa so as to be sloping at an angle equal to or greater than 30° relative to a vertical line to said surface of said substrate, depositing said layer on said reshaped mesa, and removing said layer by reactive ion etching.
Claim 6
Independent Claim
90 words
A method for avoiding residue on a vertical walled dielectric mesa of a layer to be deposited on said mesa and to be removed by reactive ion etching comprising the steps of providing a silicon substrate having said dielectric mesa on a surface thereof, reshaping a wall of said mesa so as to be sloping at an angle equal to or greater than 30° relative to a vertical line to said surface of said substrate, depositing said layer on said reshaped mesa, and removing said layer by reactive ion etching.
Claim 7
Dependent Claim
15 words
A method as described in claim 4 whereby a wall is reshaped by ion milling.
Claim 8
Dependent Claim
28 words
A method as described in claim 5 whereby the ion milling is performed so as to cause the wall to slope at an angle of 30° to 45°.
Claim 9
Dependent Claim
15 words
A method as described in claim 4 whereby polysilicon is deposited on said reshaped mesa.
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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) | 1986-06-20 | 1986-12-20 | 1987-06-21 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1990-06-20 | 1990-12-20 | 1991-06-21 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1994-06-20 | 1994-12-20 | 1995-06-21 | $7700.00 | Window Closed / Lapsed |