US4190467A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Semiconductor device production
Assignee: AT&T Inc
•
Filing: 1978-12-15
•
Granted: 1980-02-26
•
Expires: 1998-12-15
Abstract
Abstract A thermal gradient zone melting technique is provided for eliminating distortion of the migrated metal pattern by including a peripheral ring of the metal adjacent the edge of the semiconductor wafer.
Inventors
- 👤 Suei-Yuen P. Lien
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-26 17:11
CPC Classifications
C; C30; C30B; C30B13/00; C30B13/02; H; H10; H10P; H10P95/00; H10P95/50
Claims Analysis
Total Claims: 6
Claim 1
Independent Claim
103 words
A method of processing a semiconductor wafer by thermal gradient zone melting, comprising: selecting a suitable semiconductor wafer to be processed, depositing a metal suitable for thermal migration through said semiconductor wafer in a desired pattern on a first surface of said wafer, said metal pattern including a layer of metal around the periphery of said first surface of said wafer adjacent the edge of said wafer, and heating the wafer so as to cause the metal of said pattern to melt and to cause the thermal gradient migration through said semiconductor wafer in the directon of the second surface of said wafer.
Claim 2
Independent Claim
103 words
A method of processing a semiconductor wafer by thermal gradient zone melting, comprising: selecting a suitable semiconductor wafer to be processed, depositing a metal suitable for thermal migration through said semiconductor wafer in a desired pattern on a first surface of said wafer, said metal pattern including a layer of metal around the periphery of said first surface of said wafer adjacent the edge of said wafer, and heating the wafer so as to cause the metal of said pattern to melt and to cause the thermal gradient migration through said semiconductor wafer in the directon of the second surface of said wafer.
Claim 3
Dependent Claim
14 words
The method recited in claim 1 wherein said semiconductor wafer is single crystal silicon.
Claim 4
Dependent Claim
23 words
The method recited in claim 1 wherein said semiconductor wafer is single crystal silicon and wherein said surfaces are in the crystallographic direction.
Claim 5
Dependent Claim
19 words
The method recited in claim 1 wherein said semiconductor is single crystal silicon and wherein said metal is aluminum.
Claim 6
Dependent Claim
28 words
The method recited in claim 1 wherein the thickness of the peripheral metal layer is from about 8-10 microns while the layer width is from about 20-40 mils.
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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) | 1983-02-25 | 1983-08-27 | 1984-02-26 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1987-02-25 | 1987-08-27 | 1988-02-26 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1991-02-25 | 1991-08-27 | 1992-02-26 | $7700.00 | Window Closed / Lapsed |