US5504021A
Expired / Lapsed
US
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Method of fabricating thin O/N/O stacked dielectric for high-density DRAMs
Assignee: United Microelectronics Corp
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Filing: 1994-08-15
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Granted: 1996-04-02
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Expires: 2014-08-15
Abstract
Abstract A method of fabricating a super thin O/N/O stacked dielectric by oxidizing a thin nitride layer in low pressure oxygen for high-density DRAMs is disclosed. A thin nitride layer with a thickness of approximately 20 Å to 60 Å is formed over the surface of a silicon substrate. The nitride layer is oxidized in pure oxygen ambient of 0.01 Torr to 76 Torr at a temperature from 750° C. to 950° C. for approximately 10 to 60 minutes. A super thin oxide/nitride/oxide (O/N/O) stacked dielectric exhibiting a low leakage current and high reliability for use in high-density DRAMs is formed by the aforementioned low-pressure dry-oxidation procedure.
Inventors
- 👤 Gary Hong
- 👤 Huang-Chung Cheng
- 👤 Huan-Ping Su
- 👤 Han-Wen Liu
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-09 03:23
CPC Classifications
H; H10; H10D; H10D1/00; H10D1/60; H10D1/68; Y; Y10; Y10S; Y10S438/00; Y10S438/954
Claims Analysis
Total Claims: 3
Claim 1
Independent Claim
82 words
A method of fabricating an O/N/O stacked dielectric on a silicon substrate, comprising the steps of: (a) forming a nitride layer on a surface of said silicon substrate wherein said nitride layer has a thickness between 20 Å and 60 Å; and (b) oxidizing said nitride layer in pure oxygen ambient of 0.01 Torr to 76 Torr at a temperature between 750° C. and 950° C. for approximately 10 to 60 minutes to form an oxide/nitride/oxide (O/N/O) stacked dielectric on said substrate.
Claim 2
Independent Claim
82 words
A method of fabricating an O/N/O stacked dielectric on a silicon substrate, comprising the steps of: (a) forming a nitride layer on a surface of said silicon substrate wherein said nitride layer has a thickness between 20 Å and 60 Å; and (b) oxidizing said nitride layer in pure oxygen ambient of 0.01 Torr to 76 Torr at a temperature between 750° C. and 950° C. for approximately 10 to 60 minutes to form an oxide/nitride/oxide (O/N/O) stacked dielectric on said substrate.
Claim 3
Dependent Claim
34 words
The method of claim 1 wherein said nitride layer has a thickness of approximately 42 Å and is oxidized at a temperature of approximately 850° C. for approximately 30 minutes at approximately 0.1 Torr.
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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) | 1999-04-02 | 1999-10-02 | 2000-04-02 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2003-04-02 | 2003-10-02 | 2004-04-02 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2007-04-02 | 2007-10-02 | 2008-04-02 | $7700.00 | Window Closed / Lapsed |