Patent US2585722A successfully refreshed from Google Patents.
Patent US3342650A successfully refreshed from Google Patents.
US3342650A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method of making semiconductor devices by double masking
Assignee: Hitachi Ltd
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Filing: 1965-02-02
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Granted: 1967-09-19
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Expires: 1985-02-02
Abstract
No abstract record available.
Inventors
- 👤 Seki Takeo
- 👤 Tauchi Shoji
- 👤 Takagi Takeshi
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-25 18:05
CPC Classifications
H; H10; H10P; H10P95/00; H10D; H10D99/00; H10P14/00; H10P14/60; H10P14/63; H10P14/6302; H10P14/6304; H10P14/6306; H10P14/6308; H10P14/6309; H10P14/6322; H10P14/6326; H10P14/6328; H10P14/6334; H10P14/65; H10P14/6516; H10P14/6518; H10P14/69; H10P14/692; H10P14/6921; H10P14/69215; H10P14/6928; Y; Y10; Y10S; Y10S148/00; Y10S148/043; Y10S148/051; Y10S148/053; Y10S148/106
Claims Analysis
Total Claims: 2
Claim 1
Independent Claim
187 words
A METHOD OF FABRICATING A SEMICONDUCTOR DEVICE COMPRISING THE STEPS OF: (A) FORMING A FIRST ELECTRIC INSULATOR FILM ON THE SURFACE OF A SEMICONDUCTOR SUBSTRATE; (B) FORMING A PLURALITY OF PERFORATIONS THROUGH SAID FILM, SAID PERFORATIONS TERMINATING AT THE SURFACE OF SAID SUBSTRATE; (C) DEPOSITING A SECOND FILM ON SAID FIRST INSULATOR FILM TO COVER IT AND PORTIONS OF THE SURFACE OF SAID SUBSTRATE WHICH HAVE BEEN EXPOSED BY SAID PERFORATIONS, SAID SECOND FILM HAVING A HIGHER RATE OF ETCHING BY THE SAME ETCHANT THAN SAID INSULATOR FILM AND BEING EFFECTIVE FOR SHIELDING AGAINST DIFFUSION OF ACTIVE IMPURITIES: (D) FORMING AT LEAST ONE OPENING THROUGH SAID SECOND FILM, SAID OPENING TERMINATING AT THE SURFACE OF SAID SUBSTRATE BY WAY OF AT LEAST ONE OF SAID PERFORATIONS, EXTENDING THROUGH SAID INSULATOR FILM WHILE THE REMAINING PERFORATIONS ARE STILL COVERED BY SAID SECOND FILM; (E) SELECTIVELY DIFFUSING AN ACTIVE IMPURITY INTO SAID SEMICONDUCTOR SUBSTRATE THROUGH SAID OPENING EXTENDING THROUGH SAID SECOND FILM; AND (F) REMOVING SAID SECOND FILM TO REESTABLISH SAID PERFORATIONS THROUGH SAID INSULATOR FILM, THEREBY TO REEXPOSE PORTIONS OF THE SURFACE OF SAID SUBSTRATE THROUGH SAID PERORATIONS.
Claim 2
Independent Claim
187 words
A METHOD OF FABRICATING A SEMICONDUCTOR DEVICE COMPRISING THE STEPS OF: (A) FORMING A FIRST ELECTRIC INSULATOR FILM ON THE SURFACE OF A SEMICONDUCTOR SUBSTRATE; (B) FORMING A PLURALITY OF PERFORATIONS THROUGH SAID FILM, SAID PERFORATIONS TERMINATING AT THE SURFACE OF SAID SUBSTRATE; (C) DEPOSITING A SECOND FILM ON SAID FIRST INSULATOR FILM TO COVER IT AND PORTIONS OF THE SURFACE OF SAID SUBSTRATE WHICH HAVE BEEN EXPOSED BY SAID PERFORATIONS, SAID SECOND FILM HAVING A HIGHER RATE OF ETCHING BY THE SAME ETCHANT THAN SAID INSULATOR FILM AND BEING EFFECTIVE FOR SHIELDING AGAINST DIFFUSION OF ACTIVE IMPURITIES: (D) FORMING AT LEAST ONE OPENING THROUGH SAID SECOND FILM, SAID OPENING TERMINATING AT THE SURFACE OF SAID SUBSTRATE BY WAY OF AT LEAST ONE OF SAID PERFORATIONS, EXTENDING THROUGH SAID INSULATOR FILM WHILE THE REMAINING PERFORATIONS ARE STILL COVERED BY SAID SECOND FILM; (E) SELECTIVELY DIFFUSING AN ACTIVE IMPURITY INTO SAID SEMICONDUCTOR SUBSTRATE THROUGH SAID OPENING EXTENDING THROUGH SAID SECOND FILM; AND (F) REMOVING SAID SECOND FILM TO REESTABLISH SAID PERFORATIONS THROUGH SAID INSULATOR FILM, THEREBY TO REEXPOSE PORTIONS OF THE SURFACE OF SAID SUBSTRATE THROUGH SAID PERORATIONS.
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) | 1970-09-18 | 1971-03-20 | 1971-09-19 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1974-09-18 | 1975-03-20 | 1975-09-19 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1978-09-18 | 1979-03-20 | 1979-09-19 | $7700.00 | Window Closed / Lapsed |