US5338968A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method of forming isolated regions of oxide
Assignee: STMicroelectronics lnc USA
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Filing: 1992-09-04
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Granted: 1994-08-16
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Expires: 2012-09-04
Abstract
Abstract A method is provided for forming isolated regions of oxide of an integrated circuit, and an integrated circuit formed according to the same. A pad oxide layer is formed over the integrated circuit. A nitrogen doped polysilicon layer is formed over the pad oxide layer. A thick nitride layer is then formed over the nitrogen doped polysilicon layer. An opening is formed in the nitride layer and the nitrogen doped polysilicon layer exposing a portion of the pad oxide layer. The nitrogen doped polysilicon layer is annealed encapsulating the polysilicon layer in silicon nitride. A field oxide region is then formed in the opening.
Inventors
- 👤 Robert Hodges
- 👤 Frank Bryant
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-30 10:27
CPC Classifications
H; H10; H10P; H10P14/00; H10P14/60; H10P14/61; Y; Y10; Y10S; Y10S148/00; Y10S148/015; Y10S148/117; Y10S257/00; Y10S257/905; Y10S257/912; Y10S257/914
Claims Analysis
Total Claims: 4
Claim 1
Independent Claim
77 words
A structure consisting of a portion of a semiconductor integrated circuit, comprising: a substrate; a pad oxide layer disposed over a portion of the substrate; a field oxide region disposed over all remaining portions of the substrate not covered by the pad oxide layer; a layer of polysilicon disposed over the pad oxide layer, wherein the polysilicon layer has a polysilicon/nitride compound in outer regions thereof; and a nitride layer disposed over the nitrogen doped polysilicon layer.
Claim 2
Dependent Claim
77 words
A structure consisting of a portion of a semiconductor integrated circuit, comprising: a substrate; a pad oxide layer disposed over a portion of the substrate; a field oxide region disposed over all remaining portions of the substrate not covered by the pad oxide layer; a layer of polysilicon disposed over the pad oxide layer, wherein the polysilicon layer has a polysilicon/nitride compound in outer regions thereof; and a nitride layer disposed over the nitrogen doped polysilicon layer.
Claim 3
Dependent Claim
28 words
The structure of claim 1, wherein the polysilicon layer comprises a layer characteristic of being implanted with nitrogen and then annealed, encapsulating the polysilicon layer in silicon nitride.
Claim 4
Dependent Claim
20 words
The structure of claim 1, wherein the polysilicon/nitride compound is an oxidation barrier, and wherein the polysilicon is not oxidized.
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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) | 1997-08-15 | 1998-02-14 | 1998-08-16 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2001-08-15 | 2002-02-14 | 2002-08-16 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2005-08-15 | 2006-02-14 | 2006-08-16 | $7700.00 | Window Closed / Lapsed |