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US5534455A
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Method for protecting a stacked gate edge in a semiconductor device from self aligned source (SAS) etch
Assignee: Cypress Semiconductor Corp
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Filing: 1995-05-02
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Granted: 1996-07-09
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Expires: 2015-05-02
Abstract
Abstract A process for protecting the stacked gate edge of a semiconductor device is disclosed. The process provides for providing a spacer formation before the self aligned source (SAS) etch is accomplished. By providing the spacer formation prior to the SAS etch, tunnel oxide integrity is much improved and the source junction implant profile is much more uniform because the silicon around the source region is not gouged away.
Inventors
- 👤 David K. Y. Liu
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-29 16:13
CPC Classifications
H; H10; H10B; H10B41/00; H10B41/40; H10B41/42; H10B41/43; H10B41/44; H10P; H10P50/00; H10P50/71
Claims Analysis
Total Claims: 8
Claim 1
Independent Claim
77 words
A method for protecting a stacked gate edge to minimize damage to a tunnel oxide and to maintain source junction uniformity of a semiconductor device comprising the sequential steps of: (a) providing the stacked gate edge on the semiconductor device; (b) performing a source implant on the semiconductor device; (c) providing a spacer on the stacked gate edge; (d) providing a self aligned source (SAS) etch on the semiconductor device; and (e) providing a source connection implant.
Claim 2
Independent Claim
77 words
A method for protecting a stacked gate edge to minimize damage to a tunnel oxide and to maintain source junction uniformity of a semiconductor device comprising the sequential steps of: (a) providing the stacked gate edge on the semiconductor device; (b) performing a source implant on the semiconductor device; (c) providing a spacer on the stacked gate edge; (d) providing a self aligned source (SAS) etch on the semiconductor device; and (e) providing a source connection implant.
Claim 3
Dependent Claim
25 words
The method of claim 1 in which the stacked gate edge providing step (a) further comprises the step of: (a1) etching the stacked gate edge.
Claim 4
Dependent Claim
41 words
The method of claim 2 in which the stacked gate edge providing step (a) further comprises the step of: (a2) providing a resist strip; (a3) providing an oxidation layer; and (a4) providing a mask and an implant on the semiconductor device.
Claim 5
Dependent Claim
31 words
The method of claim 1 in which the spacer step (c) further comprises the steps of: (c1) depositing a spacer material; and (c2) etching the spacer material to form the spacer.
Claim 6
Dependent Claim
29 words
The method of claim 1 in which the SAS etch providing step (d) further comprises the steps of: (d1) providing an SAS mask; and (d2) etching the SAS mask.
Claim 7
Dependent Claim
40 words
The method of claim 5 in which the source connection implant providing step (e) further comprises the steps of: (e1) implanting a dopant to connect a source line from a source region to a field region of the semiconductor device.
Claim 8
Dependent Claim
52 words
The method of claim 1 in which the source implant performing step (b) comprises: (b1) providing a resist mask on the semiconductor device; (b2) providing a source implant on the semiconductor device; and (b3) providing a resist strip to form a continuous source profile of the semiconductor device to facilitate uniform erasure.
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) | 1999-07-09 | 2000-01-08 | 2000-07-09 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2003-07-09 | 2004-01-08 | 2004-07-09 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2007-07-09 | 2008-01-08 | 2008-07-09 | $7700.00 | Window Closed / Lapsed |