US3825997A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method for making semiconductor device
Assignee: Sony Corp
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Filing: 1972-05-22
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Granted: 1974-07-30
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Expires: 1992-05-22
Abstract
Abstract A method for constructing planar type semiconductor devices in which PN junctions of the device are exposed through an opening formed in a first insulating layer on the surface of the device and is then covered with a low resistivity polycrystalline semiconductor layer which is then covered with a second insulating layer such that voltage may be applied to the polycrystalline layer to provide a planar semiconductor substrate which has high break-down voltage.
Inventors
- 👤 K Wakamiya
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-08 16:32
CPC Classifications
H; H10; H10D; H10D64/00; H10D64/111; H10D99/00; H10P; H10P95/00; H10W; H10W20/00; H10W20/40; H10W74/00; H10W74/40
Claims Analysis
Total Claims: 10
Claim 1
Independent Claim
191 words
The method of forming a semiconductor substrate device comprising the steps of: a. forming an insulating layer on one surface of said substrate, b. forming a layer of polycrystalline layer over said insulating layer, c. forming an etching mask with windows of photo resist over said polycrystalline layer, d. etching through said mask to the surface of said substrate to form a window, e. diffusing an impurity of type opposite to the impurity type of said substrate through said window into said substrate to form a base region and which highly dopes said polycrystalline layer, and a second insulating layer formed over said polycrystalline layer and said window, f. etching through said second insulating layer formed in step (e) and diffusing an impurity of the same type as said substrate to form an emitter region in said base region, g. forming windows to said base region and said polycrystalline layer, h. forming a first conductor which extends through said windows to said base region and said polycrystalline layer, i. forming a window to said emitter region, and j. forming a second conductor which extends through said window to said emitter region.
Claim 2
Independent Claim
191 words
The method of forming a semiconductor substrate device comprising the steps of: a. forming an insulating layer on one surface of said substrate, b. forming a layer of polycrystalline layer over said insulating layer, c. forming an etching mask with windows of photo resist over said polycrystalline layer, d. etching through said mask to the surface of said substrate to form a window, e. diffusing an impurity of type opposite to the impurity type of said substrate through said window into said substrate to form a base region and which highly dopes said polycrystalline layer, and a second insulating layer formed over said polycrystalline layer and said window, f. etching through said second insulating layer formed in step (e) and diffusing an impurity of the same type as said substrate to form an emitter region in said base region, g. forming windows to said base region and said polycrystalline layer, h. forming a first conductor which extends through said windows to said base region and said polycrystalline layer, i. forming a window to said emitter region, and j. forming a second conductor which extends through said window to said emitter region.
Claim 3
Dependent Claim
21 words
The method of claim 1 comprising the additional step of forming a third electrode on the other surface of said substrate.
Claim 4
Dependent Claim
28 words
The method of claim 2 wherein said substrate has a high impurity concentration portion adjacent said other surface and a low impurity concentration portion adjacent said one surface.
Claim 5
Dependent Claim
29 words
The method of claim 1 wherein said insulating layer is step (a) is composed of insulating material selected from the group of silicon dioxide, silicon nitride, and aluminum oxide.
Claim 6
Dependent Claim
22 words
The method of claim 1 wherein the etching mask of step (c) is composed photo resist selected from the group KPR, AZ.
Claim 7
Independent Claim
252 words
The method of forming a semiconductor substrate device comprising the steps of: a. forming a silicon layer of a first conductivity type on a silicon substrate of a second conductivity type and divided by regions of a second conductivity type, b. forming an insulating layer on said silicon layer, c. forming a polycrystalline layer over said insulating layer with a second insulating layer on said polycrystalline layer, d. forming a first window through the first and second insulating layers and said polycrystalline layer to said silicon layer of first conductivity type, e. diffusing an impurity of a second conductivity type through said first window to form a base region in said silicon layer of first conductivity type and said impurity also diffusing into said polycrystalline layer, f. forming a window through said second insulating layer and said polycrystalline layer to the silicon substrate of a first conductivity type, g. forming a third window through said second insulating layer to said base region, h. diffusing an impurity of a first conductivity type through said third window to form an emitter region, i. forming a fourth window through said second insulating layer to said polycrystalline layer, j. forming a collector electrode which extends through said second window to said collector, k. forming an emitter electrode which extends through said third window to said emitter, l. forming a base electrode which extends through first window to said base region, and m. forming a polycrystalline electrode which extends through said fourth window to said polycrystalline layer.
Claim 8
Independent Claim
252 words
The method of forming a semiconductor substrate device comprising the steps of: a. forming a silicon layer of a first conductivity type on a silicon substrate of a second conductivity type and divided by regions of a second conductivity type, b. forming an insulating layer on said silicon layer, c. forming a polycrystalline layer over said insulating layer with a second insulating layer on said polycrystalline layer, d. forming a first window through the first and second insulating layers and said polycrystalline layer to said silicon layer of first conductivity type, e. diffusing an impurity of a second conductivity type through said first window to form a base region in said silicon layer of first conductivity type and said impurity also diffusing into said polycrystalline layer, f. forming a window through said second insulating layer and said polycrystalline layer to the silicon substrate of a first conductivity type, g. forming a third window through said second insulating layer to said base region, h. diffusing an impurity of a first conductivity type through said third window to form an emitter region, i. forming a fourth window through said second insulating layer to said polycrystalline layer, j. forming a collector electrode which extends through said second window to said collector, k. forming an emitter electrode which extends through said third window to said emitter, l. forming a base electrode which extends through first window to said base region, and m. forming a polycrystalline electrode which extends through said fourth window to said polycrystalline layer.
Claim 9
Dependent Claim
31 words
The method of claim 6 comprising forming a conductive layer on the other side of said substrate and electrically connecting said conductive layer on the other side to said polycrystalline layer.
Claim 10
Dependent Claim
29 words
The method of claim 6 wherein said insulating layer in step (b) is composed of insulating material selected from the group of silicon dioxide, silicon nitride, and aluminum oxide.
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) | 1977-07-29 | 1978-01-28 | 1978-07-30 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1981-07-29 | 1982-01-28 | 1982-07-30 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1985-07-29 | 1986-01-28 | 1986-07-30 | $7700.00 | Window Closed / Lapsed |