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US3573571A
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Surface-diffused transistor with isolated field plate
Assignee: General Electric Co
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Filing: 1968-05-01
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Granted: 1971-04-06
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Expires: 1988-05-01
Abstract
Abstract A surface-diffused transistor exhibiting high stability and low collector capacitance includes a metallic field plate buried within an insulating film which covers the active major wafer surface thereof and passivates a surface-adjacent collector junction. Metal field plate is fixed to a negative potential and prevents inversion of a surface-adjacent region of the P-type semiconductor, thereby preventing surface leakage and increased capacitance.
Inventors
- 👤 Dale M Brown
- 👤 William E Engeler
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-28 14:08
CPC Classifications
H; H10; H10D; H10D64/00; H10D64/111; H10D10/00; H10D10/40; H10D10/421; H10D84/00; H10D84/80; H10D84/82; H10D84/83; H10D84/85
Claims Analysis
Total Claims: 9
Claim 1
Independent Claim
13 words
The device of claim 1 wherein said electrical conductor is a metallic film.
Claim 2
Dependent Claim
36 words
The device of claim 2 wherein said one conductivity region is P-type and said metallic film is coincident with the boundary of said P-type region at its intersection with an N-type region at said major surface.
Claim 3
Dependent Claim
69 words
The device of claim 2 wherein said device is a junction transistor having a collector region, a base region surface-diffused into said collector region, and an emitter region surface-diffused into said base region and said buried metallic plate is superposed over said one conductivity type region and one edge thereof is coincident with the intersection of the junction between the collector and base region thereof with said major surface.
Claim 4
Dependent Claim
29 words
The device of claim 2 wherein said device is a PNP surface diFfused transistor, said one conductivity type is a P-type regions, and said fixed electrical potential is negative.
Claim 5
Dependent Claim
30 words
The device of claim 5 wherein said P-type region is the collector and said buried metallic film has an edge coincident with but superposed over the base collector junction thereof.
Claim 6
Dependent Claim
54 words
The device of claim 6 wherein said buried film is laterally bifurcated and constitutes an inner portion and an outer portion surrounding said inner portion and defining therebetween a spacing which substantially defines the lateral extent of a major surface-adjacent portion of said P-type collector having greatly enhanced conductivity and constituting a guard ring.
Claim 7
Dependent Claim
15 words
The device of claim 6 wherein said metal film is permeable to acceptor activator atoms.
Claim 8
Independent Claim
190 words
A method of forming a surface-diffused semiconductor device exhibiting a high degree of stability against surface channel effects due to surface-adjacent majority carrier depletion at the interface thereof with an insulator and including the steps of: a. providing a semiconductor body having a major surface region of one electrical conductivity; b. forming a first insulating film over said major surface region; c. forming a film of a metallic conductor over said insulating film; d. forming a second insulating film over said conducting film; e. forming a pattern over said second insulating film and over said region of one electrical conductivity type; f. removing a portion of said second insulating film and said conducting film to define a diffusion aperture; g. diffusing an opposite conductivity inducing activator through said aperture and into said one conductivity surface region to form an asymmetrically conductive junction between said regions which junction intersects said major surface substantially under the edges of said aperture; h. said aperture defining the extent of said opposite conductivity region automatically registering said conductive film over the remaining surface-adjacent portion of said one-conductivity region and in registry with said junction-surface intersection.
Claim 9
Dependent Claim
17 words
The method of claim 9 wherein said one conductivity region is a collector region of a transistor.
References Cited (Backward Citations)
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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) | 1974-04-05 | 1974-10-05 | 1975-04-06 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1978-04-05 | 1978-10-05 | 1979-04-06 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1982-04-05 | 1982-10-05 | 1983-04-06 | $7700.00 | Window Closed / Lapsed |