US3615951A
Expired / Lapsed
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Method for etching copper
Assignee: International Business Machines Corp
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Filing: 1969-06-20
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Granted: 1971-10-26
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Expires: 1989-06-20
Abstract
Abstract A method for subtractive etching copper adapted to form very fine line patterns. In the method a mask is deposited on the copper surface, the copper surface exposed to an environment containing an oxidizing agent which causes the formation of an adherent self thickness limiting coating of a copper compound on the exposed surface, the resultant adherent coating removed in a second environment, and the steps of forming the coating and removing repeated until the desired amount of copper has been removed.
Inventors
- 👤 Jack R Franco
- 👤 Paul A Totta
- 👤 James F White
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-30 08:52
CPC Classifications
H; H05; H05K; H05K3/00; H05K3/02; H05K3/06; H05K3/067; C; C23; C23F; C23F1/00; C23F1/02; H10; H10P; H10P95/00; H10W; H10W20/00; H10W20/40; H05K2203/00; H05K2203/03; H05K2203/0315; H05K2203/0369; H05K2203/11; H05K2203/1142; H05K2203/1157
Claims Analysis
Total Claims: 12
Claim 1
Independent Claim
36 words
The method of claim 1 wherein said first environment includes an oxidizing agent selected from the group consisting of reagents of oxygen, sulfur, iodine, bromine and mixtures thereof in an oxidation state capable of oxidizing Cu.
Claim 2
Dependent Claim
29 words
The method of claim 2 wherein the adherent coating of a Cu compound is selected from the group consisting of Cu iodide, Cu oxide, Cu sulfide, and mixtures thereof.
Claim 3
Dependent Claim
12 words
The method of claim 1 wherein the adherent coating is Cu oxide.
Claim 4
Dependent Claim
16 words
The method of claim 4 wherein said first environment is an aqueous solution including iodide ions.
Claim 5
Dependent Claim
19 words
The method of claim 4 wherein the Cu oxide coating is removed with an ammoniacal solution of sodium sulfite.
Claim 6
Dependent Claim
11 words
The method of claim 4 wherein said first environment includes oxygen.
Claim 7
Dependent Claim
20 words
The method of claim 7 wherein said first environment is air at elevated temperatures on the order of 200* C.
Claim 8
Dependent Claim
28 words
The method of claim 8 wherein said masking layer is a layer of metal selected from the group consisting of Cr, Ti, Mo, Ta, W and mixtures thereof.
Claim 9
Dependent Claim
15 words
The method of claim 4 wherein said first environment is a solution including bromide ions.
Claim 10
Dependent Claim
11 words
The method of claim 4 wherein said first environment includes H2O2.
Claim 11
Dependent Claim
12 words
The method of claim 1 wherein the adherent coating is Cu sulfide.
Claim 12
Dependent Claim
14 words
The method of claim 12 wherein said first environment at least includes hydrogen sulfide.
References Cited (Backward Citations)
No citation records indexed.
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1974-10-25 | 1975-04-26 | 1975-10-26 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1978-10-25 | 1979-04-26 | 1979-10-26 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1982-10-25 | 1983-04-26 | 1983-10-26 | $7700.00 | Window Closed / Lapsed |