US4229247A
Expired / Lapsed
US
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Glow discharge etching process for chromium
Assignee: International Business Machines Corp
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Filing: 1978-12-26
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Granted: 1980-10-21
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Expires: 1998-12-26
Abstract
Abstract Chromium is etched in a glow discharge without attack on Al/Cu, Si, SiO 2 , and Si 3 N 4 layers by etching in a low pressure ambient atmosphere containing a polychlorinated organic compound such as CCl 4 , water, and a material selected from the group consisting of the noble gases and oxygen.
Inventors
- 👤 George T. Chiu
- 👤 James R. Kitcher
- 👤 Gunars M. Ozols
- 👤 Bryant N. Zingerman
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-25 16:38
CPC Classifications
C; C23; C23F; C23F4/00; H; H10; H10P; H10P50/00; H10P50/20; H10P50/26; H10P50/264; H10P50/266; H10P50/267
Claims Analysis
Total Claims: 19
Claim 1
Independent Claim
78 words
A process for selectively etching chromium comprising exposing chromium to a glow discharge in a low pressure ambient atmosphere comprising a mixture of from about 5 to 50 percent by volume of a polychlorinated organic compound and from about 50 to 95 percent by volume of a material selected from the group consisting of a noble gas and oxygen to which mixture is added from 5 to 30 percent by volume, based on said mixture, of water vapor.
Claim 2
Dependent Claim
78 words
A process for selectively etching chromium comprising exposing chromium to a glow discharge in a low pressure ambient atmosphere comprising a mixture of from about 5 to 50 percent by volume of a polychlorinated organic compound and from about 50 to 95 percent by volume of a material selected from the group consisting of a noble gas and oxygen to which mixture is added from 5 to 30 percent by volume, based on said mixture, of water vapor.
Claim 3
Dependent Claim
15 words
The process of claim 1 wherein the pressure is from about 5 to 50 milli-torr.
Claim 4
Dependent Claim
112 words
A process for selectively etching chromium from a workpiece comprising placing the workpiece on a first electrode in a chamber and subjecting the chromium to a glow discharge formed by electrically biasing the first electrode relative to a second electrode, in a low pressure ambient atmosphere comprising a mixture from about 5 to 50 percent by volume of a polychlorinated organic compound, from about 50 to 95 percent by volume of a material selected from the group consisting of a noble gas and oxygen and 5 to 30 percent by volume based on said mixture, of water vapor, said ambient atmosphere having a pressure in the range of about 5to 50 milli-torr.
Claim 5
Dependent Claim
112 words
A process for selectively etching chromium from a workpiece comprising placing the workpiece on a first electrode in a chamber and subjecting the chromium to a glow discharge formed by electrically biasing the first electrode relative to a second electrode, in a low pressure ambient atmosphere comprising a mixture from about 5 to 50 percent by volume of a polychlorinated organic compound, from about 50 to 95 percent by volume of a material selected from the group consisting of a noble gas and oxygen and 5 to 30 percent by volume based on said mixture, of water vapor, said ambient atmosphere having a pressure in the range of about 5to 50 milli-torr.
Claim 6
Dependent Claim
35 words
The process of claim 3 wherein the workpiece is a silicon semiconductor wafer including a layer of silicon dioxide on which is formed a layer of chromium which is partially covered by a masking layer.
Claim 7
Dependent Claim
14 words
The process of claim 3 wherein the polychlorinated organic compound is CCl 4 .
Claim 8
Dependent Claim
15 words
The process of claim 3 wherein the pressure is from about 10 to 30 milli-torr.
Claim 9
Dependent Claim
10 words
The process of claim 6 wherein the material is oxygen.
Claim 10
Dependent Claim
12 words
The process of claim 6 wherein the material is a noble gas.
Claim 11
Dependent Claim
11 words
The process of claim 8 wherein the noble gas is argon.
Claim 12
Dependent Claim
95 words
A process for selectively etching chromium in the presence of a layer of material which is also exposed to the etching atmosphere comprising exposing the chromium to a glow discharge in an ambient atmosphere comprising from about 2 to 5 parts by volume of a polychlorinated organic compound, from about 5 to 8 parts by volume of a material selected from the group consisting of a noble gas and oxygen and from about 1 to 2 parts by volume of water vapor, the ambient atmosphere having a pressure of from about 5 to 50 milli-torr.
Claim 13
Dependent Claim
95 words
A process for selectively etching chromium in the presence of a layer of material which is also exposed to the etching atmosphere comprising exposing the chromium to a glow discharge in an ambient atmosphere comprising from about 2 to 5 parts by volume of a polychlorinated organic compound, from about 5 to 8 parts by volume of a material selected from the group consisting of a noble gas and oxygen and from about 1 to 2 parts by volume of water vapor, the ambient atmosphere having a pressure of from about 5 to 50 milli-torr.
Claim 14
Dependent Claim
10 words
The process of claim 10 wherein the material is oxygen.
Claim 15
Dependent Claim
13 words
The process of claim 10 wherein the layer of mateiral comprises silicon dioxide.
Claim 16
Dependent Claim
12 words
The process of claim 10 wherein the layer of material comprises aluminum/copper.
Claim 17
Dependent Claim
13 words
The process of claim 10 wherein the layer of material comprises silicon nitride.
Claim 18
Dependent Claim
12 words
The process of claim 10 wherein the material is a noble gas.
Claim 19
Dependent Claim
11 words
The process of claim 15 wherein the noble gas is argon.
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) | 1983-10-21 | 1984-04-21 | 1984-10-21 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1987-10-21 | 1988-04-21 | 1988-10-21 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1991-10-21 | 1992-04-21 | 1992-10-21 | $7700.00 | Window Closed / Lapsed |