US4445966A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method of plasma etching of films containing chromium
Assignee: Atmel Corp
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Filing: 1983-06-20
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Granted: 1984-05-01
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Expires: 2003-06-20
Abstract
Abstract A method of etching a thin film containing chromium using fluorine or a fluorine containing compound without leaving an electrically conductive residue is described.
Inventors
- 👤 Robert J. Carlson
- 👤 Daniel W. Youngner
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-26 08:33
CPC Classifications
H; H10; H10P; H10P50/00; H10P50/20; H10P50/26; H10P50/264; H10P50/266; H10P50/267; H10P50/268
Claims Analysis
Total Claims: 24
Claim 1
Independent Claim
49 words
A method of etching a film containing chromium and silicon in an etching chamber, said method comprising: preheating said film; filling said etching chamber with an etchant gas including fluorine and oxygen while said film is contained therein; and providing a radio frequency electrical excitation to said etchant gas.
Claim 2
Independent Claim
49 words
A method of etching a film containing chromium and silicon in an etching chamber, said method comprising: preheating said film; filling said etching chamber with an etchant gas including fluorine and oxygen while said film is contained therein; and providing a radio frequency electrical excitation to said etchant gas.
Claim 3
Dependent Claim
22 words
The method of claim 1 wherein said etching chamber is preheated to a temperature in the range 35° C. to 100° C.
Claim 4
Dependent Claim
17 words
The method of claim 2 wherein said film is preheated to a temperature of approximately 70° C.
Claim 5
Dependent Claim
25 words
The method of claim 1 wherein said etchant gas is maintained at a pressure in the range 0.2 to 0.7 torr in said etching chamber.
Claim 6
Dependent Claim
16 words
The method of claim 4 wherein said etchant gas includes CF 4 and O 2 .
Claim 7
Dependent Claim
21 words
The method of claim 5 wherein said film is preheated to a temperature in the range 35° C. to 100° C.
Claim 8
Dependent Claim
17 words
The method of claim 6 wherein said film is preheated to a temperature of approximately 70° C.
Claim 9
Dependent Claim
20 words
The method of claim 1 wherein said radio frequency electrical discharge is in the range 150 watts to 300 watts.
Claim 10
Dependent Claim
16 words
The method of claim 8 wherein said etchant gas includes CF 4 and O 2 .
Claim 11
Dependent Claim
21 words
The method of claim 9 wherein said film is preheated to a temperature in the range 35° C. to 100° C.
Claim 12
Dependent Claim
17 words
The method of claim 9 wherein said film is preheated to a temperature of approximately 70° C.
Claim 13
Dependent Claim
23 words
The method of claim 1 wherein said preheating is accomplished by a plasma including nitrogen, said plasma being produced in said etching chamber.
Claim 14
Dependent Claim
21 words
The method of claim 12 wherein said film is preheated to a temperature in the range 35° C. to 100° C.
Claim 15
Dependent Claim
17 words
The method of claim 13 wherein said film is preheated to a temperature of approximately 70° C.
Claim 16
Dependent Claim
16 words
The method of claim 12 wherein said etchant gas includes CF 4 and O 2 .
Claim 17
Dependent Claim
21 words
The method of claim 15 wherein said film is preheated to a temperature in the range 35° C. to 100° C.
Claim 18
Dependent Claim
24 words
The method of claim 16 wherein said etchant gas is maintained at a pressure in the range 0.2 to 0.7 in said etching chamber.
Claim 19
Dependent Claim
18 words
The method of claim 17 wherein said electrical discharge is in the range 150 watts to 300 watts.
Claim 20
Dependent Claim
17 words
The method of claim 18 wherein said film is preheated to a temperature of approximately 70° C.
Claim 21
Independent Claim
95 words
A method of etching a film including chromium, silicon, and nitrogen, said method comprising: placing said film in an etching chamber; evacuating said etching chamber; introducing nitrogen gas into said etching chamber; providing a first radio frequency electrical excitation to said nitrogen gas said excitation being maintained until said film reaches a temperature in the range 35° C. to 100° C.; removing said nitrogen gas from said etching chamber; introducing an etchant gas containing CF 4 and O 2 into said etching chamber; and providing a second radio frequency electrical excitation to said etchant gas.
Claim 22
Independent Claim
95 words
A method of etching a film including chromium, silicon, and nitrogen, said method comprising: placing said film in an etching chamber; evacuating said etching chamber; introducing nitrogen gas into said etching chamber; providing a first radio frequency electrical excitation to said nitrogen gas said excitation being maintained until said film reaches a temperature in the range 35° C. to 100° C.; removing said nitrogen gas from said etching chamber; introducing an etchant gas containing CF 4 and O 2 into said etching chamber; and providing a second radio frequency electrical excitation to said etchant gas.
Claim 23
Dependent Claim
28 words
The method of claim 20 wherein said etchant gas is maintained at a pressure in the range 0.2 to 0.7 torr during said second radio frequency electrical discharge.
Claim 24
Dependent Claim
21 words
The method of claim 21 wherein said radio frequency electrical discharge is in the range of 150 watts to 300 watts.
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) | 1987-05-01 | 1987-10-31 | 1988-05-01 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1991-05-01 | 1991-10-31 | 1992-05-01 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1995-05-01 | 1995-10-31 | 1996-05-01 | $7700.00 | Window Closed / Lapsed |