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US5562801A
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Method of etching an oxide layer
Assignee: Adeia Semiconductor Technologies LLC
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Filing: 1994-12-07
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Granted: 1996-10-08
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Expires: 2014-12-07
Abstract
Abstract A method of etching an oxide layer is disclosed. First, a resist layer is formed on an oxide layer on a substrate. Next, a photosensitive layer is formed on the oxide layer and patterned to expose regions of the oxide layer to be removed. The exposed regions may overlie a nitride layer, and may overlie a structure such as a polysilicon gate. The etch is performed such that polymer deposits on the photosensitive layer, thus eliminating interactions between the photosensitive layer and the plasma. In this way, a simple etch process allows for good control of the etch, resulting in reduced aspect ratio dependent etch effects, high oxide:nitride selectivity, and good wall angle profile control.
Inventors
- 👤 James E. Nulty
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-29 08:46
CPC Classifications
H; H10; H10P; H10P50/00; H10P50/20; H10P50/28; H10P50/282; H10P50/283; H10P50/73; H10W; H10W20/00; H10W20/01; H10W20/031; H10W20/069; H10W20/071; H10W20/081
Claims Analysis
Total Claims: 15
Claim 1
Independent Claim
84 words
A method of etching an oxide layer comprising: forming a photosensitive layer on said oxide layer which is on a substrate; forming a first opening in said photosensitive layer to expose a portion of said oxide layer; exposing said substrate to a plasma, said plasma etching said exposed portion of said oxide layer and forming a first layer on said photosensitive layer, wherein the combined thickness of said first layer and said photosensitive layer is greater than the thickness of said photosensitive layer alone.
Claim 2
Independent Claim
84 words
A method of etching an oxide layer comprising: forming a photosensitive layer on said oxide layer which is on a substrate; forming a first opening in said photosensitive layer to expose a portion of said oxide layer; exposing said substrate to a plasma, said plasma etching said exposed portion of said oxide layer and forming a first layer on said photosensitive layer, wherein the combined thickness of said first layer and said photosensitive layer is greater than the thickness of said photosensitive layer alone.
Claim 3
Dependent Claim
14 words
The method as described in claim 1 wherein said first layer comprises a polymer.
Claim 4
Dependent Claim
23 words
The method as described in claim 1 wherein said plasma is formed in a flow comprising C 2 H 2 F 4 .
Claim 5
Dependent Claim
15 words
The method as described in claim 3 wherein said flow further comprises CHF 3 .
Claim 6
Dependent Claim
23 words
The method as described in claim 1 wherein said plasma is formed using an RF power in the range of approximately 300-400 W.
Claim 7
Dependent Claim
25 words
The method as described in claim 1 wherein said plasma is formed between two electrodes having a spacing in the range of approximately 1.3-1.8 inches.
Claim 8
Dependent Claim
25 words
The method as described in claim 3 wherein said plasma is formed between two electrodes having a spacing in the range of approximately 1.3-1.8 inches.
Claim 9
Dependent Claim
18 words
The method as described in claim 1 wherein said oxide layer opening exposes a corner of a structure.
Claim 10
Dependent Claim
18 words
The method as described in claim 3 wherein said oxide layer opening exposes a corner of a structure.
Claim 11
Dependent Claim
18 words
The method as described in claim 6 wherein said oxide layer opening exposes a corner of a structure.
Claim 12
Dependent Claim
25 words
The method as described in claim 8 wherein said substrate comprises a nitride layer underlying said oxide layer, said nitride layer disposed on said corner.
Claim 13
Dependent Claim
51 words
The method as described in claim 1 wherein said photosensitive layer is the uppermost layer on said substrate prior to said formation of said first layer, and wherein at least a portion of said photosensitive layer having said first layer formed thereon is substantially parallel to a surface of said substrate.
Claim 14
Dependent Claim
51 words
The method as described in claim 3 wherein said photosensitive layer is the uppermost layer on said substrate prior to said formation of said first layer, and wherein at least a portion of said photosensitive layer having said first layer formed thereon is substantially parallel to a surface of said substrate.
Claim 15
Dependent Claim
51 words
The method as described in claim 6 wherein said photosensitive layer is the uppermost layer on said substrate prior to said formation of said first layer, and wherein at least a portion of said photosensitive layer having said first layer formed thereon is substantially parallel to a surface of said substrate.
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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) | 1999-10-08 | 2000-04-08 | 2000-10-08 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2003-10-08 | 2004-04-08 | 2004-10-08 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2007-10-08 | 2008-04-08 | 2008-10-08 | $7700.00 | Window Closed / Lapsed |