US4775644A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Zero bird-beak oxide isolation scheme for integrated circuits
Assignee: LSI Corp
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Filing: 1987-06-03
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Granted: 1988-10-04
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Expires: 2007-06-03
Abstract
Abstract The present method provides for formation of isolation oxide without "bird-beak" extensions thereof through the use of a nitride mask in contact with the surface of a semiconductor substrate on both sides of a patterned oxide layer, on which substrate the isolation oxide is grown.
Inventors
- 👤 Roger T. Szeto
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-28 10:13
CPC Classifications
H; H10; H10P; H10P14/00; H10P14/60; H10P14/63; H10P14/6302; H10P14/6304; H10W; H10W10/00; H10W10/01; H10W10/011; H10W10/012; H10P14/61; H10P14/6316; H10P50/00; H10P50/73; H10W10/10; H10W10/13
Claims Analysis
Total Claims: 6
Claim 1
Independent Claim
153 words
A method of forming isolation oxide in a semiconductor device comprising: providing a layer of semiconductor material having a surface; providing an oxide layer over a portion of the surface of the layer of semiconductor material; providing a first nitride layer over a portion of the oxide layer; patterning the first nitride layer to expose a portion of the oxide layer; patterning the oxide layer to undercut the first nitride layer, using the patterned first nitride layer as a mask; providing a second nitride layer over at least a portion of the resulting structure, in contact with the patterned first nitride layer and the surface of the layer of semiconductor material; patterning the second nitride layer to leave an exposed portion of the surface of the layer of semiconductor material, spaced from the oxide layer by nitride material; and growing an isolation oxide in the exposed portion of the layer of semiconductor material.
Claim 2
Independent Claim
153 words
A method of forming isolation oxide in a semiconductor device comprising: providing a layer of semiconductor material having a surface; providing an oxide layer over a portion of the surface of the layer of semiconductor material; providing a first nitride layer over a portion of the oxide layer; patterning the first nitride layer to expose a portion of the oxide layer; patterning the oxide layer to undercut the first nitride layer, using the patterned first nitride layer as a mask; providing a second nitride layer over at least a portion of the resulting structure, in contact with the patterned first nitride layer and the surface of the layer of semiconductor material; patterning the second nitride layer to leave an exposed portion of the surface of the layer of semiconductor material, spaced from the oxide layer by nitride material; and growing an isolation oxide in the exposed portion of the layer of semiconductor material.
Claim 3
Dependent Claim
18 words
The method of claim 1 wherein the second nitride layer is provided in contact with the oxide layer.
Claim 4
Dependent Claim
31 words
The method of claim 1 wherein the exposed surface portion of the layer of semiconductor material is spaced from the oxide layer by nitride material of the patterned second nitride layer.
Claim 5
Dependent Claim
25 words
The method of claim 3 and further comprising the step of removing, subsequent to growing said isolation oxide, the remainder of the first nitride layer.
Claim 6
Dependent Claim
14 words
The method of claim 4 wherein the first and second nitride layers are deposited.
References Cited (Backward Citations)
US3648125A
Cited
US3961999A
Cited
US4118728A
Cited
US4292156A
Cited
US4272308A
Cited
US4271583A
Cited
US4533429A
Cited
US4622096A
Cited
US4561172A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1991-10-04 | 1992-04-04 | 1992-10-04 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1995-10-04 | 1996-04-04 | 1996-10-04 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1999-10-04 | 2000-04-04 | 2000-10-04 | $7700.00 | Window Closed / Lapsed |