US3725145A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method for manufacturing semiconductor devices
Assignee: Hitachi Ltd
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Filing: 1970-03-27
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Granted: 1973-04-03
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Expires: 1990-03-27
Abstract
Abstract SEMICONDUCTOR DEVICES CONTAINING TWO DIFFUSED REGIONS WITH DIFFERENT DEPTHS FORMED IN A COMMON SEMICONDUCTOR SUBSTRATE ARE MADE BY, FOR EXAMPLE, FIRST SELECTIVELY DIFFUSING GERMANIUM INTO THE SURFACE OF AN N-TYPE SILICON CRYSTALLINE SUBSTRATE AND, THEREAFTER, SELECTIVELY DIFFUSING BORON INTO THE REGION CONTAINING THEN DIFFUSED GERMANIUM AS WELL AS INTO ANOTHER SURFACE PORTION OF THE SUBSTRATE WHERE THE GERMANIUM HAS NOT BEEN DIFUSED.
Inventors
- 👤 M Maki
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-30 19:56
CPC Classifications
H; H10; H10P; H10P95/00; H10D; H10D84/00; H10D84/01; H10D84/02; H10D84/03; H10D84/038; H10D84/40; H10D84/401; H10D84/403; H10D89/00; H10D89/60; H10D89/601; H10D89/611; H10D99/00; Y; Y10; Y10S; Y10S148/00; Y10S148/037; Y10S148/038; Y10S148/04; Y10S148/049; Y10S148/085; Y10S148/097; Y10S148/151; Y10S252/00; Y10S252/95
Claims Analysis
Total Claims: 0
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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) | 1976-04-02 | 1976-10-02 | 1977-04-03 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1980-04-02 | 1980-10-02 | 1981-04-03 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1984-04-02 | 1984-10-02 | 1985-04-03 | $7700.00 | Window Closed / Lapsed |