Patent US4525221A successfully refreshed from Google Patents.
US4525221A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Alloying of aluminum metallization
Assignee: RCA Corp
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Filing: 1984-05-16
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Granted: 1985-06-25
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Expires: 2004-05-16
Abstract
Abstract An improvement in the rapid alloying of aluminum metallization on a silicon substrate is provided. The structure is heated to alloying temperature for under a minute in a suitable heating means in a reducing atmosphere and rapidly cooled to under 200° C. in not longer than about one minute after cessation of heating. A preferred reducing atmosphere is forming gas.
Inventors
- 👤 Chung P. Wu
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-04 20:47
CPC Classifications
H; H10; H10W; H10W20/00; H10W20/01; H10W20/031; H10W20/064; H10P; H10P95/00; Y; Y10; Y10S; Y10S438/00; Y10S438/937
Claims Analysis
Total Claims: 9
Claim 1
Independent Claim
83 words
In a method of heating a structure comprising a silicon substrate and a layer of aluminum metallization at least partially in contact therewith to a temperature sufficient to alloy said contact using heating means that will supply a pulse of energy such that the structure is heated to alloying temperature for less than one minute and cooled to below about 200° C. in not longer than about one minute after cessation of heating, the improvement comprising heating said structure in a reducing atmosphere.
Claim 2
Dependent Claim
83 words
In a method of heating a structure comprising a silicon substrate and a layer of aluminum metallization at least partially in contact therewith to a temperature sufficient to alloy said contact using heating means that will supply a pulse of energy such that the structure is heated to alloying temperature for less than one minute and cooled to below about 200° C. in not longer than about one minute after cessation of heating, the improvement comprising heating said structure in a reducing atmosphere.
Claim 3
Dependent Claim
18 words
The improved method in accordance with claim 1, wherein the heating means is a graphite strip heating means.
Claim 4
Dependent Claim
20 words
The improved method in accordance with claim 1, wherein the heating means is pulsed, high intensity, visible light heating means.
Claim 5
Dependent Claim
30 words
The improved method in accordance with claim 1, wherein the structure is heated to a temperature of from about 490° to 540° C. for from about 2 to 10 seconds.
Claim 6
Dependent Claim
16 words
The improved method in accordance with claim 4, wherein the reducing atmosphere is a hydrogen-containing gas.
Claim 7
Dependent Claim
15 words
The improved method in accordance with claim 5, wherein the reducing atmosphere is forming gas.
Claim 8
Dependent Claim
29 words
The improved method in accordance with claim 1, wherein the aluminum metallization is an alloy of aluminum and silicon containing up to about 3 percent by weight of silicon.
Claim 9
Dependent Claim
19 words
The improved method in accordance with claim 7, wherein the alloy contains about one percent by weight of silicon.
References Cited (Backward Citations)
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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) | 1988-06-24 | 1988-12-24 | 1989-06-25 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1992-06-24 | 1992-12-24 | 1993-06-25 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1996-06-24 | 1996-12-24 | 1997-06-25 | $7700.00 | Window Closed / Lapsed |