Patent US3767494A successfully refreshed from Google Patents.
US3767494A
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Method for manufacturing a semiconductor photosensitive device
Assignee: Toshiba Corp
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Filing: 1971-10-12
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Granted: 1973-10-23
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Expires: 1991-10-12
Abstract
Abstract A method for manufacturing thin semiconductor photosensitive devices having a flat surface comprising the steps depositing a high resistivity silicon epitaxial growth layer on a low resistivity silicon substrate, forming a plurality of PN junctions in the growth layer and etching the substrate to remove the central portion thereof so as to expose the corresponding flat surface portion of the growth layer with an etchant of HF, HNO3 and CH3COOH which selectively etches the low resistivity silicon without etching the high resistivity silicon.
Inventors
- 👤 H Muraoka
- 👤 A Fujii
- 👤 T Ohashi
- 👤 T Yasui
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-24 13:34
CPC Classifications
H; H10; H10P; H10P50/00; H10P50/60; H10P50/64; H10P50/642; H10D; H10D99/00; Y; Y10; Y10S; Y10S148/00; Y10S148/007; Y10S148/051; Y10S148/135; Y10S438/00; Y10S438/977
Claims Analysis
Total Claims: 3
Claim 1
Independent Claim
24 words
The method of claim 1 wherein the etching rate of said substrate is more than 100 times the etching rate of said silicon layer.
Claim 2
Dependent Claim
14 words
The method of claim 1 wherein said protective layer is formed of a wax.
Claim 3
Dependent Claim
35 words
The method of claim 1 wherein said protective layer is removed from the substrate beneath it following said etching step (d) and an electrode is formed on the substrate where the protective layer was removed.
References Cited (Backward Citations)
US3616345A
Cited
US3616348A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1976-10-22 | 1977-04-23 | 1977-10-23 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1980-10-22 | 1981-04-23 | 1981-10-23 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1984-10-22 | 1985-04-23 | 1985-10-23 | $7700.00 | Window Closed / Lapsed |