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US4662986A
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Planarization method and technique for isolating semiconductor islands
Assignee: Signetics Corp
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Filing: 1985-06-27
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Granted: 1987-05-05
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Expires: 2005-06-27
Abstract
Abstract A technique for producing planarized semiconductor surfaces and for isolating semiconductor islands.
Inventors
- 👤 Sheldon C. P. Lim
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-27 04:07
CPC Classifications
G; G03; G03F; G03F7/00; H; H10; H10P; H10P95/00; H10P95/06; H10P95/062; H10P95/064; H10W; H10W10/00; H10W10/01; H10W10/011; H10W10/014; H10W10/10; H10W10/17
Claims Analysis
Total Claims: 6
Claim 1
Independent Claim
104 words
A method of planarization of a surface of a semiconductor structure having a step of a certain height on said surface, said step being a glass over metal step, said method including coating said surface with a first photoresist layer; selectively exposing said first photoresist layer to radiation and developing said layer so that a portion of the layer over said step is removed and that a portion adjoining said step remains; and coating the remainder of said first layer and said step with a second photoresist layer of a desirable thickness whereby the surface of said second layer is rendered smooth and planar.
Claim 2
Independent Claim
104 words
A method of planarization of a surface of a semiconductor structure having a step of a certain height on said surface, said step being a glass over metal step, said method including coating said surface with a first photoresist layer; selectively exposing said first photoresist layer to radiation and developing said layer so that a portion of the layer over said step is removed and that a portion adjoining said step remains; and coating the remainder of said first layer and said step with a second photoresist layer of a desirable thickness whereby the surface of said second layer is rendered smooth and planar.
Claim 3
Dependent Claim
15 words
A method according to claim 1, wherein said exposed radiation is light through a mask.
Claim 4
Dependent Claim
18 words
A method according to claim 2, wherein said first photoresist layer is as thick as said certain height.
Claim 5
Dependent Claim
29 words
A method according to claim 3, wherein said second photoresist layer and said glass are etched until a planarized surface of a metal island surrounded by glass is produced.
Claim 6
Dependent Claim
11 words
A method according to claim 4, wherein said semiconductor is silicon.
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) | 1990-05-04 | 1990-11-03 | 1991-05-05 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1994-05-04 | 1994-11-03 | 1995-05-05 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1998-05-04 | 1998-11-03 | 1999-05-05 | $7700.00 | Window Closed / Lapsed |