Patent US4391731A successfully refreshed from Google Patents.
Patent US3761328A successfully refreshed from Google Patents.
US3761328A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method of manufacturing semiconductor devices
Assignee: Toshiba Corp
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Filing: 1970-06-23
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Granted: 1973-09-25
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Expires: 1990-06-23
Abstract
Abstract AN INSULATING FILM MAINLY COMPOSED OF SILICON DIOXIDE AND HAVING AT LEAST ONE OPENING IS FORMED ON THE SURFACE OF A SEMICONDUCTOR WAFER AND THEN A READILY ECTHABLE FILM IS APPLIED ON THE EXPOSED SURFACE OF THE OPENING, WHICH IS MAINLY COMPOSED OF SILICON DIOXIDE AND CONTAINS AN IMPURITY ELEMENT ADAPTED TO FORM A SHALLOW IMPURITY LEVEL AND AN ADDITIVE SUBSTANCE WHICH INCREASES THE ETCHING SPEED OF THE READILY ETCHABLE FILM AFTER DIFFUSED WITH THE IMPURITY TO A VALUE HIGHER THAN THAT OF THE INSULATING FILM AND WHICH DOES NOT IMPAIR THE ELECTRICAL CHARACTERISTICS OF THE DIFFUSED AREA.
Inventors
- 👤 T Abe
- 👤 M Konaka
- 👤 T Narita
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-26 15:05
CPC Classifications
H; H10; H10P; H10P95/00; H10D; H10D99/00; H10P14/00; H10P14/60; H10P14/63; H10P14/6326; H10P14/6328; H10P14/6329; H10P14/6334; H10P14/66; H10P14/662; H10P14/668; H10P14/6681; H10P14/6682; H10P14/69; H10P14/692; H10P14/6921; H10P14/69215; H10P14/6922; H10P14/6923; Y; Y10; Y10S; Y10S148/00; Y10S148/04; Y10S148/043; Y10S148/106; Y10S148/118; Y10S148/141; Y10S148/145; Y10S148/147; Y10S148/151
Claims Analysis
Total Claims: 0
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References Cited (Backward Citations)
No citation records indexed.
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1976-09-24 | 1977-03-26 | 1977-09-25 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1980-09-24 | 1981-03-26 | 1981-09-25 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1984-09-24 | 1985-03-26 | 1985-09-25 | $7700.00 | Window Closed / Lapsed |