Patent US3847677A successfully refreshed from Google Patents.
US3847677A
Expired / Lapsed
US
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Method of manufacturing semiconductor devices
Assignee: Hitachi Ltd
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Filing: 1973-01-24
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Granted: 1974-11-12
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Expires: 1993-01-24
Abstract
Abstract An improved process for the manufacture of a semiconductor device having a plurality of bipolar type semiconductor elements formed on a substrate and isolated from each other by diffusion layers. Each diffusion layer is formed by a diffusion layer diffused from an impurity source buried in the substrate into a semiconductor layer epitaxially grown on the substrate and another diffusion layer diffused from the surface of the epitaxially grown semiconductor layer until it is combined with the first-mentioned diffusion layer.
Inventors
- 👤 T Takeda
- 👤 Y Nakazawa
- 👤 H Ikeda
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-27 19:42
CPC Classifications
H; H10; H10P; H10P95/00; H10W; H10W10/00; H10W10/01; H10W10/031; H10W10/30; Y; Y10; Y10S; Y10S148/00; Y10S148/007; Y10S148/037; Y10S148/085; Y10S148/151; Y10S257/00; Y10S257/918
Claims Analysis
Total Claims: 8
Claim 1
Independent Claim
132 words
IN A METHOD OF MANUFACTURING A SEMICONDUCTOR DEVICE, THE IMPROVEMENT COMPRISING THE STEPS OF: A. IMPLANTING AN IMPURITY INTO AT LEAST ONE PRESCRIBED PORTION OF A SEMICONDUCTOR SUBSTRATE OF A FIRST CONDUCTIVITY TYPE TO FORM AT LEAST ONE BURIED LAYER OF SAID FIRST CONDUCTIVITY TYPE, SAID BURIED LAYER HVING A GREATER IMPURITY NON-CONTIGUOUS TO A PRINCIPAL SURFACE OF SAID SUBSTRATE; B. EPITAXIALLY GROWING A SEMICONDUCTOR LAYER OF A SECOND CONDUCTIVITY TYPE, OPPOSITE SAID FIRST CONDUCTIVELY TYPE, ON SAID PRINCIPAL SURFACE OF SAID SUBSTRATE; AND C. SELECTIVELY DIFFUSING AN IMPURITY INTO SAID SEMICONDUCTOR LAYER TO FORM A FIRST DIFFUSION AN IMPURITY OF SAID FIRST CONDCTIVITY TYPE IN SAID SEMICONDUCTOR LAYER WHICH DIFFUSES TO A DEPTH TO BECOME CONTIGUOUS WITH A SECOND DIFFUSION LAYER WHICH HAS FORMED FROM THE OUTDIFFUSION OF THE IMPURITY IN
Claim 2
Dependent Claim
132 words
IN A METHOD OF MANUFACTURING A SEMICONDUCTOR DEVICE, THE IMPROVEMENT COMPRISING THE STEPS OF: A. IMPLANTING AN IMPURITY INTO AT LEAST ONE PRESCRIBED PORTION OF A SEMICONDUCTOR SUBSTRATE OF A FIRST CONDUCTIVITY TYPE TO FORM AT LEAST ONE BURIED LAYER OF SAID FIRST CONDUCTIVITY TYPE, SAID BURIED LAYER HVING A GREATER IMPURITY NON-CONTIGUOUS TO A PRINCIPAL SURFACE OF SAID SUBSTRATE; B. EPITAXIALLY GROWING A SEMICONDUCTOR LAYER OF A SECOND CONDUCTIVITY TYPE, OPPOSITE SAID FIRST CONDUCTIVELY TYPE, ON SAID PRINCIPAL SURFACE OF SAID SUBSTRATE; AND C. SELECTIVELY DIFFUSING AN IMPURITY INTO SAID SEMICONDUCTOR LAYER TO FORM A FIRST DIFFUSION AN IMPURITY OF SAID FIRST CONDCTIVITY TYPE IN SAID SEMICONDUCTOR LAYER WHICH DIFFUSES TO A DEPTH TO BECOME CONTIGUOUS WITH A SECOND DIFFUSION LAYER WHICH HAS FORMED FROM THE OUTDIFFUSION OF THE IMPURITY IN
Claim 3
Dependent Claim
57 words
A method according to claim 1, wherein step (b) comprises the steps of epitaxially growing said layer on said principal surface of said substrate while simultaneously outdiffusing the impurity in said at least one prescribed portion of said substrate from said portion through said substrate toward the principal surface thereof on which epitaxial growth is taking place.
Claim 4
Dependent Claim
58 words
A method according to claim 2, further comprising the step of diffusing an impurity of said second conductivity type into said substrate through the principal surface thereof prior to said step (a) to form a diffused surface region in said substrate, said diffused surface region having an impurity concentration greater than that of said epitaxially grown semiconductor layer.
Claim 5
Dependent Claim
86 words
A method according to claim 3, further comprising the steps of selectively diffusing an impurity into the surface of said semiconductor layer to form a base diffusion layer therein of said first conductivity type, selectively diffusing an emitter and a collector contact diffusion layer of said second conductivity type and of a higher impurity concentration than said epitaxially grown semiconductor layer in said epitaxially grown layer and in said base diffusion layer respectively, and forming electrode contacts on said base, emitter and collector contact diffusion layers.
Claim 6
Dependent Claim
63 words
A method according to claim 1, wherein step (a) comprises implanting said impurity to form said at least one buried layer with a prescribed impurity concentration and thickness, and wherein said method further includes the step of effecting a drive-in diffusion of the impurity in said layer into said substrate so as to controllably modify the thickness thereof, prior to said step (b).
Claim 7
Dependent Claim
57 words
A method according to claim 5, wherein step (b) comprises the steps of epitaxially growing said layer on said principal surface of said substrate while simultaneously outdiffusing the impurity in said at least one prescribed portion of said substrate from said portion through said substrate toward the principal surface thereof on which epitaxial growth is taking place.
Claim 8
Dependent Claim
23 words
A method according to claim 1, wherein step (a) comprises implanting an ion impurity into said substrate while monitoring the ion beam current.
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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) | 1977-11-11 | 1978-05-13 | 1978-11-12 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1981-11-11 | 1982-05-13 | 1982-11-12 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1985-11-11 | 1986-05-13 | 1986-11-12 | $7700.00 | Window Closed / Lapsed |