US4422897A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Process for selectively etching silicon
Assignee: Massachusetts Institute of Technology
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Filing: 1982-05-25
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Granted: 1983-12-27
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Expires: 2002-05-25
Abstract
Abstract A process is provided for selectively etching silicon by means of a plasma etching composition wherein an etching target is connected to a radio frequency voltage and a source of silicon and oxygen is provided with the plasma etching composition in order to minimize etching of a masking composition.
Inventors
- 👤 Christopher M. Horwitz
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-25 23:07
CPC Classifications
H; H10; H10P; H10P50/00; H10P50/20; H10P50/24; H10P50/242
Claims Analysis
Total Claims: 13
Claim 1
Independent Claim
93 words
The process for selectively etching silicon in preference to a masking material on a surface of said silicon which comprises positioning a patterned masking material on said silicon, positioning said silicon on a target connected to a radio frequency electrode, introducing an etchant gas composition into said chamber under conditions to convert said etchant gas composition to a plasma, providing a source of oxygen and silicon to the interior of said chamber under conditions to deposit silicon dioxide selectively on said masking material layer and to etch silicon selectively from said silicon layer.
Claim 2
Dependent Claim
93 words
The process for selectively etching silicon in preference to a masking material on a surface of said silicon which comprises positioning a patterned masking material on said silicon, positioning said silicon on a target connected to a radio frequency electrode, introducing an etchant gas composition into said chamber under conditions to convert said etchant gas composition to a plasma, providing a source of oxygen and silicon to the interior of said chamber under conditions to deposit silicon dioxide selectively on said masking material layer and to etch silicon selectively from said silicon layer.
Claim 3
Dependent Claim
12 words
The process of claim 1 wherein said masking material is silicon dioxide.
Claim 4
Dependent Claim
12 words
The process of claim 1 wherein said masking material is magnesium fluoride.
Claim 5
Dependent Claim
11 words
The process of claim 1 wherein said masking material is aluminum.
Claim 6
Dependent Claim
18 words
The process of claim 3 wherein the etchant gas comprises silicon tetrafluoride as a source of silicon also.
Claim 7
Dependent Claim
18 words
The process of claim 4 wherein the etchant gas comprises silicon tetrafluoride as a source of silicon also.
Claim 8
Dependent Claim
18 words
The process of claim 1 wherein the etchant gas comprises silicon tetrachloride as a source of silicon also.
Claim 9
Dependent Claim
18 words
The process of claim 2 wherein the etchant gas comprises silicon tetrachloride as a source of silicon also.
Claim 10
Dependent Claim
18 words
The process of claim 3 wherein the etchant gas comprises silicon tetrachloride as a source of silicon also.
Claim 11
Dependent Claim
18 words
The process of claim 4 wherein the etchant gas comprises silicon tetrachloride as a source of silicon also.
Claim 12
Dependent Claim
18 words
The process of claim 1 wherein the etchant gas comprises silicon tetrafluoride as a source of silicon also.
Claim 13
Dependent Claim
18 words
The process of claim 2 wherein the etchant gas comprises silicon tetrafluoride as a source of silicon also.
References Cited (Backward Citations)
US4333793A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1986-12-26 | 1987-06-27 | 1987-12-27 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1990-12-26 | 1991-06-27 | 1991-12-27 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1994-12-26 | 1995-06-27 | 1995-12-27 | $7700.00 | Window Closed / Lapsed |