US4308089A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method for preventing corrosion of Al and Al alloys
Assignee: Hitachi Ltd
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Filing: 1980-05-09
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Granted: 1981-12-29
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Expires: 2000-05-09
Abstract
Abstract Disclosed is a method for preventing corrosion of Al and Al alloys processed by the dry-etching method, which comprises (i) the step of sputtering Al or Al alloy in an ammonia-containing atmosphere and (ii) the step of washing the sputtered Al or Al alloy with an alkaline aqueous solution and then with water after termination of the step (i). According to this method, corrosion of Al or Al alloy by halogen element-containing substances stuck to Al or Al alloy during the dry-etching treatment can be effectively prevented.
Inventors
- 👤 Shinya Iida
- 👤 Kazuyoshi Ueki
- 👤 Tatsumi Mizutani
- 👤 Hideo Komatsu
- 👤 Kado Hirobe
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-25 20:31
CPC Classifications
H; H10; H10P; H10P70/00; H10P70/20; H10P70/27; H10P70/273; C; C23; C23F; C23F4/00; H10P95/00
Claims Analysis
Total Claims: 15
Claim 1
Independent Claim
46 words
A method for preventing corrosion of Al and Al alloys, which comprises (i) the step of sputtering Al or Al alloy in an atmosphere containing ammonia and (ii) the step of washing the Al or Al alloy with a liquid after termination of the step (i).
Claim 2
Independent Claim
46 words
A method for preventing corrosion of Al and Al alloys, which comprises (i) the step of sputtering Al or Al alloy in an atmosphere containing ammonia and (ii) the step of washing the Al or Al alloy with a liquid after termination of the step (i).
Claim 3
Dependent Claim
37 words
A method for preventing corrosion of Al and Al alloys according to claim 1 wherein the step of sputtering Al and Al alloy in an atmosphere containing CF 4 is carried out prior to said step (i).
Claim 4
Dependent Claim
33 words
A method for preventing corrosion of Al and Al alloys according to claim 1 or 2 wherein the Al or Al alloy is one that has been processed according to the dry-etching method.
Claim 5
Dependent Claim
36 words
A method for preventing corrosion of Al and Al alloys according to claim 3 wherein the dry-etching method comprises discharging a halogen element-containing gas and processing the Al or Al alloy with formed ions or radicals.
Claim 6
Dependent Claim
66 words
A method for preventing corrosion of Al and Al alloys according to claim 4 wherein the halogen element-containing gas is a gas containing at least one member selected from the group consisting of HCl, BCl 3 , CCl 4 , PCl 3 , SiCl 4 , CCl 3 F, C 2 HCl 3 , CHBr 3 , BBr 3 , PBr 3 and SiBr 4 .
Claim 7
Dependent Claim
30 words
A method for preventing corrosion of Al and Al alloys according to claim 1 or 2 wherein the ammonia content in the ammonia-containing atmosphere is at least 10% by volume.
Claim 8
Dependent Claim
24 words
A method for preventing corrosion of Al and Al alloys according to claim 6 wherein the ammonia content is at least 50% by volume.
Claim 9
Dependent Claim
25 words
A method for preventing corrosion of Al and Al alloys according to claim 6 wherein the liquid used at the liquid washing step is water.
Claim 10
Dependent Claim
34 words
A method for preventing corrosion of Al and Al alloys according to claim 6 wherein the liquid washing comprises washing with an aqueous solution of ammonia or hydrazine hydrate and subsequent washing with water.
Claim 11
Dependent Claim
31 words
A method for preventing corrosion of Al and Al alloys according to claim 2 wherein the CF 4 content in the CF 4 -containing atmosphere is at least 10% by volume.
Claim 12
Dependent Claim
25 words
A method for preventing corrosion of Al and Al alloys according to claim 10 wherein the CF 4 content is at least 50% by volume.
Claim 13
Dependent Claim
26 words
A method for preventing corrosion of Al and Al alloys according to claim 6 wherein the ammonia-containing atmosphere contains an inert gas or CF 4 .
Claim 14
Dependent Claim
22 words
A method for preventing corrosion of Al and Al alloys according to claim 12 wherein the ammonia-containing atmosphere contains CF 4 .
Claim 15
Dependent Claim
22 words
A method for preventing corrosion of Al and Al alloys according to claim 12 wherein the ammonia-containing atmosphere contains an inert gas.
References Cited (Backward Citations)
US4148705A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1984-12-28 | 1985-06-29 | 1985-12-29 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1988-12-28 | 1989-06-29 | 1989-12-29 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1992-12-28 | 1993-06-29 | 1993-12-29 | $7700.00 | Window Closed / Lapsed |