US3419442A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Semiconductor devices
Assignee: ZF International UK Ltd
•
Filing: 1966-04-26
•
Granted: 1968-12-31
•
Expires: 1986-04-26
Abstract
No abstract record available.
Inventors
- 👤 Cockshott Charles Peter
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-04 19:11
CPC Classifications
H; H10; H10P; H10P95/00; H10D; H10D99/00; H10P32/00; H10P32/10; H10P32/14; H10P32/1408; H10P32/17; H10P32/171; H10P76/00; H10P76/40
Claims Analysis
Total Claims: 2
Claim 1
Independent Claim
162 words
A METHOD OF FORMING A THREE-LAYER SEMI-CONDUCTOR SLICE, COMPRISING THE FOLLOWING STEPS: (I) MASKING A PORTION OF ONE FACE OF A SLICE OF ONE CONDUCTIVITY TYPE AND COVERING THE REMAINDER OF SAID ONE FACE WITH A FIRST IMPURITY OF THE OPPOSITE CONDUCTIVITY TYPE; (II) SUBJECTING THE SLICE TO A DIFFUSION PROCESS AND REMOVING THE MASK; (III) THEN MASKING A PORTION OF THE OPPOSITE FACE AND COVERING THE REMAINDER OF SAID OPPOSITE FACE AND AT LEAST THOSE PORTIONS OF SAID ONE FACE OF THE SLICE NOT COVERED BY THE FIRST IMPURITY WITH A SECOND IMPURITY OF SAID OPPOSITE CONDUCTIVITY TYPE, AND SECOND IMPURITY HAVING A SLOWER RATE OF PENETRATION THAN THE FIRST IMPURITY; AND (IV) SUBJECTING THE SLICE TO A FURTHER DIFFUSION PROCESS TO CAUSE THE FIRST IMPURITY TO DIFFUSE COMPLETELY THROUGH THE SLICE ONLY IN THE REGIONS ORIGINALLY COVERED BY THE FIRST IMPURITY, SO THAT A THREE LAYER SLICE IS PRODUCED WITH ALL THREE LAYERS TERMINATING ON ONE FACE OF THE SLICE.
Claim 2
Independent Claim
162 words
A METHOD OF FORMING A THREE-LAYER SEMI-CONDUCTOR SLICE, COMPRISING THE FOLLOWING STEPS: (I) MASKING A PORTION OF ONE FACE OF A SLICE OF ONE CONDUCTIVITY TYPE AND COVERING THE REMAINDER OF SAID ONE FACE WITH A FIRST IMPURITY OF THE OPPOSITE CONDUCTIVITY TYPE; (II) SUBJECTING THE SLICE TO A DIFFUSION PROCESS AND REMOVING THE MASK; (III) THEN MASKING A PORTION OF THE OPPOSITE FACE AND COVERING THE REMAINDER OF SAID OPPOSITE FACE AND AT LEAST THOSE PORTIONS OF SAID ONE FACE OF THE SLICE NOT COVERED BY THE FIRST IMPURITY WITH A SECOND IMPURITY OF SAID OPPOSITE CONDUCTIVITY TYPE, AND SECOND IMPURITY HAVING A SLOWER RATE OF PENETRATION THAN THE FIRST IMPURITY; AND (IV) SUBJECTING THE SLICE TO A FURTHER DIFFUSION PROCESS TO CAUSE THE FIRST IMPURITY TO DIFFUSE COMPLETELY THROUGH THE SLICE ONLY IN THE REGIONS ORIGINALLY COVERED BY THE FIRST IMPURITY, SO THAT A THREE LAYER SLICE IS PRODUCED WITH ALL THREE LAYERS TERMINATING ON ONE FACE OF THE SLICE.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1971-12-31 | 1972-07-01 | 1972-12-31 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1975-12-31 | 1976-07-01 | 1976-12-31 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1979-12-31 | 1980-07-01 | 1980-12-31 | $7700.00 | Window Closed / Lapsed |