Patent US4323909A successfully refreshed from Google Patents.
US4323909A
Expired / Lapsed
US
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Planar avalanche diode with a breakdown voltage between 4 and 8 volts
Assignee: Thales SA
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Filing: 1980-04-15
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Granted: 1982-04-06
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Expires: 2000-04-15
Abstract
Abstract A diode comprising a N-type substrate in which is formed a P-type guard ring and a central diffusion of the same type but of reduced depth. Part of the central diffusion layer is interrupted by a masking island. Diffusion is for example obtained from an epitaxial layer.
Inventors
- 👤 Henri Valdmann
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-01 06:30
CPC Classifications
H; H10; H10D; H10D8/00; H10D8/50; Y; Y10; Y10S; Y10S438/00; Y10S438/983
Claims Analysis
Total Claims: 10
Claim 1
Independent Claim
91 words
A planar avalanche diode with a breakdown voltage between 4 and 8 volts incorporating a silicon substrate of a first conductivity type coated with a silica mask through which there is a diffusion to supply a layer of a second conductivity type opposite to the first, the perimeter of the diffused zone being surrounded by a deeper diffusion zone, wherein the said mask blocks the diffusion in a region within the said perimeter and at least that part of the mask within the said perimeter is covered with a protective layer.
Claim 2
Dependent Claim
91 words
A planar avalanche diode with a breakdown voltage between 4 and 8 volts incorporating a silicon substrate of a first conductivity type coated with a silica mask through which there is a diffusion to supply a layer of a second conductivity type opposite to the first, the perimeter of the diffused zone being surrounded by a deeper diffusion zone, wherein the said mask blocks the diffusion in a region within the said perimeter and at least that part of the mask within the said perimeter is covered with a protective layer.
Claim 3
Dependent Claim
19 words
A diode according to claim 1, wherein the protective layer comprises an epitaxial layer of the second conductivity type.
Claim 4
Dependent Claim
14 words
A diode according to claim 1, wherein the protective layer comprises a metallization layer.
Claim 5
Dependent Claim
15 words
A diode according to claim 1, wherein the said region is shaped like a ring.
Claim 6
Dependent Claim
16 words
A diode according to claim 1, wherein the said region is shaped like a central island.
Claim 7
Dependent Claim
14 words
A diode according to claim 1, wherein the said region has a finger shape.
Claim 8
Independent Claim
95 words
A method for the manufacture of a planar avalanche diode with a voltage between 4 and 8 volts from a silicon substrate with a first type of conductivity consisting of forming within the said substrate a deep diffusion peripheral ring, also comprising the diffusion into the perimeter defined by the deep diffusion of a layer of the same type of conductivity but less deep whilst reserving by means of an oxide mask a region inside of said perimeter below which no diffusion takes place and covering at least the said region with a supplementary layer.
Claim 9
Independent Claim
95 words
A method for the manufacture of a planar avalanche diode with a voltage between 4 and 8 volts from a silicon substrate with a first type of conductivity consisting of forming within the said substrate a deep diffusion peripheral ring, also comprising the diffusion into the perimeter defined by the deep diffusion of a layer of the same type of conductivity but less deep whilst reserving by means of an oxide mask a region inside of said perimeter below which no diffusion takes place and covering at least the said region with a supplementary layer.
Claim 10
Dependent Claim
31 words
A method according to claim 7, wherein the diffusion of the less deep layer is formed from an epitaxial layer deposited on the surface of the substrate above the said mask.
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) | 1985-04-05 | 1985-10-05 | 1986-04-06 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1989-04-05 | 1989-10-05 | 1990-04-06 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1993-04-05 | 1993-10-05 | 1994-04-06 | $7700.00 | Window Closed / Lapsed |