US4199379A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method for producing metal patterns on silicon wafers for thermomigration
Assignee: BBC Brown Boveri AG Switzerland
•
Filing: 1978-09-15
•
Granted: 1980-04-22
•
Expires: 1998-09-15
Abstract
Abstract A method of producing metal patterns on silicon wafers prior to a thermomigration process, including covering the surface of a wafer completely with a metal film, producing a photoresist pattern on portions of the metal film corresponding to a predetermined thermomigration pattern, etching away the uncovered portions of the metal film, removing the photoresist film, and annealing the remaining metal film pattern.
Inventors
- 👤 Tiberiu Mizrah
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-29 19:15
CPC Classifications
H; H10; H10P; H10P95/00; H10P95/50
Claims Analysis
Total Claims: 5
Claim 1
Independent Claim
180 words
A method for producing an aluminum metal pattern on a surface of a silicon wafer for subsequent thermomigration of said aluminum pattern into said wafer, comprising: applying to said surface of said silicon wafer an aluminum layer having a thickness in the range of from about 5 micrometers to about 100 micrometers; applying to said aluminum layer a photoresist film covering said aluminum layer at those surface portions thereof where said aluminum metal pattern is to be produced; etching away said aluminum layer in those surface portions thereof that are not covered by said photoresist film; removing said photoresist film; annealing said silicon wafer with said aluminum layer thereon in those surface portions thereof covered by said photoresist film during said etching, said annealing being effected below an eutectic point of a system consisting of said aluminum and said silicon for a period of about 30 minutes at a temperature in the range of from 560° to 570° C. in an inert gas atmosphere to form a sintered boundary layer between said silicon wafer and said aluminum metal pattern thereon.
Claim 2
Independent Claim
180 words
A method for producing an aluminum metal pattern on a surface of a silicon wafer for subsequent thermomigration of said aluminum pattern into said wafer, comprising: applying to said surface of said silicon wafer an aluminum layer having a thickness in the range of from about 5 micrometers to about 100 micrometers; applying to said aluminum layer a photoresist film covering said aluminum layer at those surface portions thereof where said aluminum metal pattern is to be produced; etching away said aluminum layer in those surface portions thereof that are not covered by said photoresist film; removing said photoresist film; annealing said silicon wafer with said aluminum layer thereon in those surface portions thereof covered by said photoresist film during said etching, said annealing being effected below an eutectic point of a system consisting of said aluminum and said silicon for a period of about 30 minutes at a temperature in the range of from 560° to 570° C. in an inert gas atmosphere to form a sintered boundary layer between said silicon wafer and said aluminum metal pattern thereon.
Claim 3
Dependent Claim
18 words
A method according to claim 1 wherein said step of producing said photoresist layer comprises: a photolithographic step.
Claim 4
Dependent Claim
22 words
A method according to claim 1, wherein said step of producing said photoresist layer comprises: forming said pattern using a screen press.
Claim 5
Dependent Claim
18 words
A method according to claim 1, wherein said silicon wafer exhibits a surface plane which is the (111)-plane.
References Cited (Backward Citations)
US2813048A
Cited
US3269861A
Cited
US3806361A
Cited
US3901736A
Cited
US4040878A
Cited
US3998662A
Cited
US4012236A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1983-04-22 | 1983-10-22 | 1984-04-22 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1987-04-22 | 1987-10-22 | 1988-04-22 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1991-04-22 | 1991-10-22 | 1992-04-22 | $7700.00 | Window Closed / Lapsed |