US4874723A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Selective etching of tungsten by remote and in situ plasma generation
Assignee: Texas Instruments Inc
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Filing: 1987-07-16
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Granted: 1989-10-17
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Expires: 2007-07-16
Abstract
Abstract A thin film etching process, wherein the rate of deposition of a robust sidewall passivant is controlled so that passivants can be continually deposited on the sidewalls of the resist pattern to change the geometry of the resist pattern during the processing step. That is, the existing pattern is modified as if a sidewall filament has been deposited on it, which can be advantageous for many purposes, without the added process complexity required by a sidewall filament process.
Inventors
- 👤 Rhett B. Jucha
- 👤 Duane E. Carter
- 👤 Cecil J. Davis
- 👤 Sue E. Crank
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-29 10:26
CPC Classifications
H; H10; H10P; H10P50/00; H10P50/20; H10P50/26; H10P50/264; H10P50/266; H10P50/267; Y; Y10; Y10S; Y10S148/00; Y10S148/051; Y10S438/00; Y10S438/963
Claims Analysis
Total Claims: 21
Claim 1
Independent Claim
139 words
A method for etching tungsten on a wafer comprising: (a) transferring a wafer into a vacuum processing chamber; (b) applying a pressure to said chamber less than ambient to maintain said chamber at less than ambient; (c) providing a sulfur containing fluorine gas to a remote plasma chamber separated from said chamber and producing a remote plasma; (d) providing a carbon containing fluorine gas to said remote plasma chamber separated from said chamber and producing a remote plasma; (e) adding a bromine containing gas to said remote plasma chamber; and (f) applying a radio frequency signal across two electrodes one of which is adjacent to the wafer and causing a plasma to be formed whose dark space is in the vicinity of the surface of the slice; (g) flowing the gas mixture over said wafer disposed within said chamber.
Claim 2
Independent Claim
139 words
A method for etching tungsten on a wafer comprising: (a) transferring a wafer into a vacuum processing chamber; (b) applying a pressure to said chamber less than ambient to maintain said chamber at less than ambient; (c) providing a sulfur containing fluorine gas to a remote plasma chamber separated from said chamber and producing a remote plasma; (d) providing a carbon containing fluorine gas to said remote plasma chamber separated from said chamber and producing a remote plasma; (e) adding a bromine containing gas to said remote plasma chamber; and (f) applying a radio frequency signal across two electrodes one of which is adjacent to the wafer and causing a plasma to be formed whose dark space is in the vicinity of the surface of the slice; (g) flowing the gas mixture over said wafer disposed within said chamber.
Claim 3
Independent Claim
64 words
A method for etching tungsten on a wafer comprising: (a) disposing said wafer in a process chamber at low pressure; (b) generating a remote plasma from a sulfur containing fluorine gas, a carbon containing fluorine, and a source of bromine; (c) introducing said remote plasma into said chamber to a face of said wafer; and (d) generating an in situ plasma with said chamber.
Claim 4
Independent Claim
64 words
A method for etching tungsten on a wafer comprising: (a) disposing said wafer in a process chamber at low pressure; (b) generating a remote plasma from a sulfur containing fluorine gas, a carbon containing fluorine, and a source of bromine; (c) introducing said remote plasma into said chamber to a face of said wafer; and (d) generating an in situ plasma with said chamber.
Claim 5
Dependent Claim
21 words
The process as set forth in claim 2 including the step of depositing passivants to control the pattern of the etch.
Claim 6
Dependent Claim
15 words
The method of claim 1 wherein the sulfur containing fluorine gas is SF 6 .
Claim 7
Dependent Claim
15 words
The method of claim 1 wherein the carbon containing fluorine gas is CF 4 .
Claim 8
Dependent Claim
12 words
The method of claim 1 wherein the bromine containing gas is HBr.
Claim 9
Dependent Claim
15 words
The method of claim 2 wherein the sulfur containing fluorine gas is SF 6 .
Claim 10
Dependent Claim
15 words
The method of claim 2 wherein the carbon containing fluorine gas is CF 4 .
Claim 11
Dependent Claim
12 words
The method of claim 2 wherein the bromine containing gas is HBr.
Claim 12
Independent Claim
95 words
A method for etching tungsten on a wafer, comprising the steps of: (a) generating free radicals from a gas containing a sulfur containing fluorine, a carbon containing fluorine, and a bromine containing gas in plasma chamber separated from a process chamber; (b) introducing said free radicals into the process chamber and to a face of a wafer; and (c) applying a radio frequency signal across two electrodes one of which is adjacent to the wafer and causing a plasma to be formed whose dark space is in the vicinity of the surface of the slice.
Claim 13
Independent Claim
95 words
A method for etching tungsten on a wafer, comprising the steps of: (a) generating free radicals from a gas containing a sulfur containing fluorine, a carbon containing fluorine, and a bromine containing gas in plasma chamber separated from a process chamber; (b) introducing said free radicals into the process chamber and to a face of a wafer; and (c) applying a radio frequency signal across two electrodes one of which is adjacent to the wafer and causing a plasma to be formed whose dark space is in the vicinity of the surface of the slice.
Claim 14
Dependent Claim
15 words
The method of claim 10 wherein the sulfur containing fluorine gas is SF 6 .
Claim 15
Dependent Claim
15 words
The method of claim 10 wherein the carbon containing fluorine gas is CF 4 .
Claim 16
Dependent Claim
12 words
The method of claim 10 wherein the bromine containing gas is HBr.
Claim 17
Independent Claim
59 words
A method for etching tungsten on a wafer, comprising the steps of: (a) generating free radicals from a gas containing a sulfur containing fluorine, a carbon containing fluorine, and a bromine containing gas as in plasma chamber separated from a process chamber; and (b) introducing said free radicals into the process chamber and to a face of a wafer.
Claim 18
Independent Claim
59 words
A method for etching tungsten on a wafer, comprising the steps of: (a) generating free radicals from a gas containing a sulfur containing fluorine, a carbon containing fluorine, and a bromine containing gas as in plasma chamber separated from a process chamber; and (b) introducing said free radicals into the process chamber and to a face of a wafer.
Claim 19
Dependent Claim
15 words
The method of claim 14 wherein the sulfur containing fluorine gas is SF 6 .
Claim 20
Dependent Claim
15 words
The method of claim 14 wherein the carbon containing fluorine gas is CF 4 .
Claim 21
Dependent Claim
12 words
The method of claim 14 wherein the bromine containing gas is HBr.
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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) | 1992-10-16 | 1993-04-17 | 1993-10-17 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1996-10-16 | 1997-04-17 | 1997-10-17 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2000-10-16 | 2001-04-17 | 2001-10-17 | $7700.00 | Window Closed / Lapsed |