Patent US2558132A successfully refreshed from Google Patents.
US3907617A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Manufacture of a high voltage Schottky barrier device
Assignee: Motorola Solutions Inc
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Filing: 1973-12-07
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Granted: 1975-09-23
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Expires: 1993-12-07
Abstract
Abstract Providing a substrate doped with a first type of impurity and having a silicon dioxide ring deposited thereon which is doped with a second type of impurity. Treating the substrate to diffuse the impurities from the ring into the substrate immediately therebelow to form a guardring aligned with the aperture through the silicon dioxide ring. Depositing barrier and contact metals within the aperture of the silicon dioxide ring to form a Schottky barrier aligned with said guardring.
Inventors
- 👤 Ross Zwernemann
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-24 13:45
CPC Classifications
H; H10; H10D; H10D8/00; H10D8/60; H10P; H10P32/00; H10P32/10; H10P32/14; H10P32/1408; H10P32/141; H10P32/17; H10P32/171; H10W; H10W74/00; H10W74/40; H10W74/43; Y; Y10; Y10S; Y10S148/00; Y10S148/043; Y10S148/139
Claims Analysis
Total Claims: 4
Claim 1
Independent Claim
191 words
AN IMPROVED METHOD OF FORMING A SCHOTTKY BARRIER DEVICE AND GUARDING COMPRISING THE STEPS OF: A. FORMING ON A SURFACE OF A SEMICONDUCTOR SUBSTRATE OF A FIRST CONDUCTIVELY TYPE A FIRST LAYER OF INSULATING MATERIAL AND FORMING AN APERTURE THROUGH SAID FIRST LAYER TO EXPOSE THE SURFACE OF SAID SUBSTRATE, B. FORMING A SECONDARY LAYER OF SILICON DIOXIDE DOPED WITH AN IMPURITY FOR PROVIDING CONDUCTIVITY OF A TYPE OPPOSITE SAID FIRST CONDUCTIVITY TYPE OVER SAID FIRST LAYER AND THE EXPOSED SURFACE OF SAID SUBSTRATE IN THE APERTURE THROUGH SAID FIRST LAYER, C. FORMING AN APERTURE THROUGH SAID SECOND LAYER WITHIN SAID APERTURE THROUGH SAID FIRST LAYER TO EXPOSE THE SURFACE OF SAID SUBSTRATE SO THAT A PORTION OF SAID SECOND LAYER REMAINS IN CONTACT WITH SAID SUBSTRATE ALONG THE ENTIRE EDGE OF THE APERTURE, D. DIFFUSING THE INPURITY OF SAID SECOND LAYER INTO THE SUBSTRATE BENETH THE PORTION OF SAID SECOND LAYER IN CONTACT WITH SAID SUBSTRATE TO FORM A GUARDING, AND E. APPLYING BARRIER AND CONTACT METALS TO THE EXPOSED SURFACE OF THE SUBSTRATE IN THE APERTURE AND A PORTION OF THE SURFACE OF SAID SECOND LAYER SURROUNDING THE APERTURE.
Claim 2
Dependent Claim
191 words
AN IMPROVED METHOD OF FORMING A SCHOTTKY BARRIER DEVICE AND GUARDING COMPRISING THE STEPS OF: A. FORMING ON A SURFACE OF A SEMICONDUCTOR SUBSTRATE OF A FIRST CONDUCTIVELY TYPE A FIRST LAYER OF INSULATING MATERIAL AND FORMING AN APERTURE THROUGH SAID FIRST LAYER TO EXPOSE THE SURFACE OF SAID SUBSTRATE, B. FORMING A SECONDARY LAYER OF SILICON DIOXIDE DOPED WITH AN IMPURITY FOR PROVIDING CONDUCTIVITY OF A TYPE OPPOSITE SAID FIRST CONDUCTIVITY TYPE OVER SAID FIRST LAYER AND THE EXPOSED SURFACE OF SAID SUBSTRATE IN THE APERTURE THROUGH SAID FIRST LAYER, C. FORMING AN APERTURE THROUGH SAID SECOND LAYER WITHIN SAID APERTURE THROUGH SAID FIRST LAYER TO EXPOSE THE SURFACE OF SAID SUBSTRATE SO THAT A PORTION OF SAID SECOND LAYER REMAINS IN CONTACT WITH SAID SUBSTRATE ALONG THE ENTIRE EDGE OF THE APERTURE, D. DIFFUSING THE INPURITY OF SAID SECOND LAYER INTO THE SUBSTRATE BENETH THE PORTION OF SAID SECOND LAYER IN CONTACT WITH SAID SUBSTRATE TO FORM A GUARDING, AND E. APPLYING BARRIER AND CONTACT METALS TO THE EXPOSED SURFACE OF THE SUBSTRATE IN THE APERTURE AND A PORTION OF THE SURFACE OF SAID SECOND LAYER SURROUNDING THE APERTURE.
Claim 3
Dependent Claim
29 words
An improved method as set forth in claim 1 wherein a lightly doped epitaxial layer is grown on a heavily doped layer and defines the surface of the substrate.
Claim 4
Dependent Claim
42 words
An improved method as set forth in claim 1 including the steps of forming the substrate into a circular disk and the first and second layers into concentric rings with the second layer extending radially inwardly slightly farther than said first layer.
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) | 1978-09-22 | 1979-03-24 | 1979-09-23 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1982-09-22 | 1983-03-24 | 1983-09-23 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1986-09-22 | 1987-03-24 | 1987-09-23 | $7700.00 | Window Closed / Lapsed |