Patent US4235648A successfully refreshed from Google Patents.
US4235648A
Expired / Lapsed
US
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Method for immersion plating very thin films of aluminum
Assignee: Motorola Solutions Inc
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Filing: 1979-04-05
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Granted: 1980-11-25
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Expires: 1999-04-05
Abstract
Abstract A method for plating very thin films of aluminum for subsequent electrical contact. The method is particularly suitable for preparation of the thin films of aluminum used in semiconductor integrated circuits for subsequent plating operations or lead bonding processes. The method comprises a removal of surface oxides in a way that does not substantially attack the very thin films of aluminum followed by immersion plating with a metal selected from the group comprising zinc, tin, nickel, silver and copper.
Inventors
- 👤 Lavoie Richardson
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-04 09:26
CPC Classifications
H; H10; H10P; H10P50/00; H10P50/20; H10P50/28; H10P50/282; H10P50/283; C; C23; C23C; C23C18/00; C23C18/54; H10P14/00; H10P14/40; H10P14/46; H10W; H10W72/00; H10W72/01; H10W72/012; H10W72/20; H10W72/251
Claims Analysis
Total Claims: 3
Claim 1
Independent Claim
70 words
A method for eliminating an aluminum oxide surface film on a substantially aluminum thin film layer comprising in order: immersing said layer in a fluoride-based solution; immersing said layer in water at about 50° C. to form a fresh surface aluminum oxide film; and immersing said layer in an immersion solution comprising the fluoride ion and a metal selected from the group consisting of zinc, tin, nickel, silver and copper.
Claim 2
Independent Claim
70 words
A method for eliminating an aluminum oxide surface film on a substantially aluminum thin film layer comprising in order: immersing said layer in a fluoride-based solution; immersing said layer in water at about 50° C. to form a fresh surface aluminum oxide film; and immersing said layer in an immersion solution comprising the fluoride ion and a metal selected from the group consisting of zinc, tin, nickel, silver and copper.
Claim 3
Dependent Claim
25 words
The method of claim 1 wherein the steps of immersion in a fluoride-based solution and hot water are repeated prior to immersion in said solution.
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US4125648A
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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) | 1983-11-25 | 1984-05-26 | 1984-11-25 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1987-11-25 | 1988-05-26 | 1988-11-25 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1991-11-25 | 1992-05-26 | 1992-11-25 | $7700.00 | Window Closed / Lapsed |