USH40H
Expired / Lapsed
US
⏱️ 0.0 years remaining
Field shields for Schottky barrier devices
Assignee: Nokia Bell Labs
•
Filing: 1984-07-18
•
Granted: 1986-04-01
•
Expires: 2004-07-18
Abstract
Abstract The present invention relates to an improved Schottky barrier device wherein the leakage current present in the reverse bias mode attributed to the presence of an electric field at the Schottky barrier (18) is significantly reduced by the inclusion of one or more field shields (22), P + -type diffusions located under the metal anode (16) of the Schottky barrier device at the Schottky barrier (18). The P + -type field shields, which are disposed in a pattern on the surface of the Schottky barrier, reduce the surface electric field present, thereby significantly reducing the leakage current related thereto.
Inventors
- 👤 William L. Buchanan, Jr.
- 👤 James E. Kohl
- 👤 Robert S. Scott
- 👤 Yiu-Huen Wong
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-07 01:53
CPC Classifications
H; H10; H10D; H10D8/00; H10D8/60; H10D62/00; H10D62/10; H10D62/102; H10D62/103; H10D62/105; H10D62/106
Claims Analysis
Total Claims: 15
Claim 1
Independent Claim
98 words
A semiconductor device which comprises a semiconductor layer of a first conductivity type; an insulating layer disposed on a surface of said semiconductor layer and having an aperture therein exposing a portion of said semiconductor layer; a metal layer disposed in said aperture and possibly onto a portion of the insulating layer, forming a Schottky barrier with said semiconductor layer therebelow; and a plurality of semiconductor regions of a second conductivity type in physical contact with both said semiconductor layer and said metal layer, each semiconductor region of said plurality of semiconductor regions being separated from one another.
Claim 2
Dependent Claim
98 words
A semiconductor device which comprises a semiconductor layer of a first conductivity type; an insulating layer disposed on a surface of said semiconductor layer and having an aperture therein exposing a portion of said semiconductor layer; a metal layer disposed in said aperture and possibly onto a portion of the insulating layer, forming a Schottky barrier with said semiconductor layer therebelow; and a plurality of semiconductor regions of a second conductivity type in physical contact with both said semiconductor layer and said metal layer, each semiconductor region of said plurality of semiconductor regions being separated from one another.
Claim 3
Dependent Claim
72 words
A semiconductor device formed in accordance with claim 1 wherein at least one of the plurality of semiconductor regions of the second conductivity type forms an annular guard ring surrounding the remaining semiconductor regions of said plurality of semiconductor regions, said annular guard ring disposed in physical contact with both the metal layer and the insulating layer, completely underlying the edge of the interface between said semiconductor layer and said metal layer.
Claim 4
Dependent Claim
49 words
A semiconductor device formed in accordance with claims 1 or 2 wherein the plurality of semiconductor regions of the second conductivity type are arranged in a geometric pattern with the separation between adjacent regions determined by the desired reverse bias leakage current and the desired forward bias voltage drop.
Claim 5
Dependent Claim
17 words
A semiconductor device formed in accordance with claim 3 wherein the geometrical pattern is a regular array.
Claim 6
Dependent Claim
17 words
A semiconductor device formed in accordance with claim 4 wherein the regular array is a rectangular lattice.
Claim 7
Dependent Claim
17 words
A semiconductor device formed in accordance with claim 4 wherein the regular array is a hexagonal lattice.
Claim 8
Dependent Claim
20 words
A semiconductor device formed in accordance with claim 4 wherein the regular array is a set of long parallel stripes.
Claim 9
Dependent Claim
19 words
A semiconductor device formed in accordance with claim 4 wherein the regular array is a set of concentric rings.
Claim 10
Dependent Claim
28 words
A semiconductor device formed in accordance with claims 1 or 2 wherein the plurality of semiconductor regions of the second conductivity type comprises a plurality of diffused regions.
Claim 11
Dependent Claim
111 words
A semiconductor device which comprises a semiconductor layer of a first conductivity type; an insulating layer disposed on a surface of said semiconductor layer and having an aperture therein exposing a portion of said semiconductor layer; a metal layer disposed in said aperture and possibly onto a portion of the insulating layer, forming a Schottky barrier with said semiconductor layer therebelow; and a semiconductor region of a second conductivity type in physical contact with both said semiconductor layer and said metal layer, said semiconductor region disposed to form a continuous pattern adjoining said Schottky barrier and extending away from the Schottky barrier edge into a central portion of the semiconductor device.
Claim 12
Dependent Claim
111 words
A semiconductor device which comprises a semiconductor layer of a first conductivity type; an insulating layer disposed on a surface of said semiconductor layer and having an aperture therein exposing a portion of said semiconductor layer; a metal layer disposed in said aperture and possibly onto a portion of the insulating layer, forming a Schottky barrier with said semiconductor layer therebelow; and a semiconductor region of a second conductivity type in physical contact with both said semiconductor layer and said metal layer, said semiconductor region disposed to form a continuous pattern adjoining said Schottky barrier and extending away from the Schottky barrier edge into a central portion of the semiconductor device.
Claim 13
Dependent Claim
22 words
A semiconductor device formed in accordance with claim 10 wherein the semiconductor region of the second conductivity type comprises a diffused region.
Claim 14
Dependent Claim
25 words
A semiconductor device formed in accordance with claims 1, 2, or 10 wherein the semiconductor layer is silicon and the insulating layer is silicon dioxide.
Claim 15
Dependent Claim
19 words
A semiconductor device formed in accordance with claims 1, 2 or 10 wherein the metal layer is nickel silicide.
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) | 1989-03-31 | 1989-09-30 | 1990-04-01 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1993-03-31 | 1993-09-30 | 1994-04-01 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1997-03-31 | 1997-09-30 | 1998-04-01 | $7700.00 | Window Closed / Lapsed |