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US5869385A
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Selectively oxidized field oxide region
Assignee: Cypress Semiconductor Corp
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Filing: 1995-12-08
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Granted: 1999-02-09
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Expires: 2015-12-08
Abstract
Abstract A field oxide region is formed with a reduced bird's beak by selectively implanting impurity atoms into the semiconductor substrate to increase the oxidation rate of the substrate and thermally oxidizing the implanted region of the semiconductor substrate. In another embodiment, a gate oxide layer having a differential thickness is formed by implanting impurity atoms into the semiconductor substrate in a selected region wherein a thick portion of the gate oxide is to be formed and thermally oxidizing the semiconductor substrate.
Inventors
- 👤 Yuan Tang
- 👤 Mark Ramsbey
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-31 10:06
CPC Classifications
H; H10; H10D; H10D84/00; H10D84/01; H10D84/02; H10D84/03; H10D84/038; H10D84/0123; H10D84/0126; H10D84/0151; H10W; H10W10/00; H10W10/01; H10W10/011; H10W10/012; H10W10/0125; H10W10/10; H10W10/13; Y; Y10; Y10S; Y10S148/00; Y10S148/138; Y10S438/00; Y10S438/964
Claims Analysis
Total Claims: 10
Claim 1
Independent Claim
87 words
A method of manufacturing a semiconductor device comprising a field oxide region, which method comprises: forming a patterned layer on an upper surface of a semiconductor substrate, which patterned layer has an opening extending through and exposing the upper surface of the semiconductor substrate; roughening and inducing crystal damage in the exposed portion of the semiconductor substrate in an amount sufficient to increase the thermal oxidation rate of the exposed portion by at least about 10%; and thermally oxidizing the substrate to form the field oxide region.
Claim 2
Independent Claim
87 words
A method of manufacturing a semiconductor device comprising a field oxide region, which method comprises: forming a patterned layer on an upper surface of a semiconductor substrate, which patterned layer has an opening extending through and exposing the upper surface of the semiconductor substrate; roughening and inducing crystal damage in the exposed portion of the semiconductor substrate in an amount sufficient to increase the thermal oxidation rate of the exposed portion by at least about 10%; and thermally oxidizing the substrate to form the field oxide region.
Claim 3
Dependent Claim
23 words
The method according to claim 1, comprising inducing crystal damage in the exposed portion of the semiconductor substrate by implanting impurity atoms therein.
Claim 4
Dependent Claim
14 words
The method according to claim 2, wherein the implanted impurity atoms are nonelectrically conductive.
Claim 5
Dependent Claim
23 words
The method according to claim 3, wherein the nonelectrically conductive impurity atoms are selected from the group consisting of silicon, germanium and argon.
Claim 6
Dependent Claim
14 words
The method according to claim 2, wherein the implanted impurity atoms are electrically conductive.
Claim 7
Dependent Claim
22 words
The method according to claim 2, comprising implanting impurity atoms at a concentration in excess of about 1×10 14 atoms/cm 2 .
Claim 8
Dependent Claim
22 words
The method according to claim 6, comprising implanting impurity atoms at a concentration ranging up to about 1×10 17 atoms/cm 2 .
Claim 9
Dependent Claim
24 words
The method according to claim 7, comprising implanting impurity atoms at a concentration of about 5×10 14 to about 5×10 15 atoms/cm 2 .
Claim 10
Dependent Claim
18 words
The method according to claim 1, comprising roughening the exposed portion of the semiconductor substrate by chemical etching.
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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) | 2002-02-08 | 2002-08-10 | 2003-02-09 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2006-02-08 | 2006-08-10 | 2007-02-09 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2010-02-08 | 2010-08-10 | 2011-02-09 | $7700.00 | Window Closed / Lapsed |