US3961353A
Expired / Lapsed
US
⏱️ 0.0 years remaining
High power semiconductor device
Assignee: International Business Machines Corp
•
Filing: 1974-10-21
•
Granted: 1976-06-01
•
Expires: 1994-10-21
Abstract
Abstract A high power semiconductor device is formed by providing a semiconductor substrate of N - conductivity, rendering the backside of same porous as by subjecting same to anodic treatment carried out in a concentrated solution of hydrofluoric acid, converting the porous region to an N + region, as by arsenic diffusion and forming an active device by conventional techniques in the top surface of the substrate. The method permits usage of high quality N - substrates and at the same time eliminates the requirement of growing thick epitaxial layers.
Inventors
- 👤 Joseph A. Aboaf
- 👤 Robert W. Broadie
- 👤 Edward M. Hull
- 👤 H. Bernhard Pogge
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-24 15:40
CPC Classifications
H; H10; H10D; H10D62/00; H10D62/10; H10D62/13; H10D62/137; H10D62/40; H10P; H10P32/00; H10P32/10; H10P32/12; H10P32/17; H10P32/171; H10P50/00; Y; Y10; Y10S; Y10S148/00; Y10S148/051; Y10S148/097; Y10S148/122
Claims Analysis
Total Claims: 7
Claim 1
Independent Claim
25 words
A semiconductor device comprising: a semiconductor substrate; and, a porous portion within said substrate doped to form a region of higher conductivity than said substrate.
Claim 2
Dependent Claim
25 words
A semiconductor device comprising: a semiconductor substrate; and, a porous portion within said substrate doped to form a region of higher conductivity than said substrate.
Claim 3
Dependent Claim
49 words
The invention defined by claim 2 wherein: said substrate has a top and back surface; said higher conductivity region extends inwardly of said back surface; and, at least one region of opposite conductivity than said high conductivity region extending from said substrate top surface for forming a semiconductor device.
Claim 4
Dependent Claim
24 words
The invention defined by claim 1 wherein said substrate is of N - conductivity and said region of high conductivity is N + .
Claim 5
Dependent Claim
27 words
The invention defined by claim 1 wherein said porous portion includes void areas on the order of 15% as measured by weight loss in said porous portion.
Claim 6
Dependent Claim
49 words
The invention defined by claim 4 wherein: said substrate has a top and back surface; said higher conductivity region extends inwardly of said back surface; and, at least one region of opposite conductivity than said high conductivity region extending from said substrate top surface for forming a semiconductor device.
Claim 7
Dependent Claim
24 words
The invention defined by claim 4 wherein said substrate is of N - conductivity and said region of high conductivity is N + .
References Cited (Backward Citations)
GB923513A
Cited
US3617822A
Cited
US3649383A
Cited
US3694276A
Cited
US3775196A
Cited
US3640806A
Cited
US3703420A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1979-06-01 | 1979-12-01 | 1980-06-01 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1983-06-01 | 1983-12-01 | 1984-06-01 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1987-06-01 | 1987-12-01 | 1988-06-01 | $7700.00 | Window Closed / Lapsed |