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Patent US3987216A successfully refreshed from Google Patents.
US3987216A
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Method of forming schottky barrier junctions having improved barrier height
Assignee: International Business Machines Corp
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Filing: 1975-12-31
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Granted: 1976-10-19
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Expires: 1995-12-31
Abstract
Abstract A method is disclosed for forming Schottky barrier junctions having improved barrier height characteristics. The method involves the use of a layer of polysilicon deposited upon the Schottky metal prior to sintering. The polysilicon layer acts as a source from which silicon is diffused into the metal during the sintering operation. After sintering the junction is quenched or cooled at a rapid rate whereby outdiffusion of the silicon is prevented.
Inventors
- 👤 Harsaran Singh Bhatia
- 👤 Harry Charles Calhoun
- 👤 Robert Leonard Melhado
- 👤 Randolph Huff Schnitzel
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-25 13:25
CPC Classifications
H; H10; H10D; H10D64/00; H10D64/01; H10D64/012; H10D64/0121; H10D64/60; H10D64/64; Y; Y10; Y10S; Y10S438/00; Y10S438/909
Claims Analysis
Total Claims: 8
Claim 1
Independent Claim
81 words
A method of producing Schottky barrier diodes comprising the steps of: depositing a metal layer upon a semiconductor layer wherein the work function of the metal exceeds the work function of the semiconductor material, depositing a layer of semiconductor material upon the metal layer; heating the semiconductor material and metal to a temperature near the eutectic point of the metal; and cooling the metal layer at a rate of at least 5° C. per second until the metal approaches room temperature.
Claim 2
Independent Claim
81 words
A method of producing Schottky barrier diodes comprising the steps of: depositing a metal layer upon a semiconductor layer wherein the work function of the metal exceeds the work function of the semiconductor material, depositing a layer of semiconductor material upon the metal layer; heating the semiconductor material and metal to a temperature near the eutectic point of the metal; and cooling the metal layer at a rate of at least 5° C. per second until the metal approaches room temperature.
Claim 3
Dependent Claim
17 words
The method of claim 1 wherein said metal layer comprises aluminum deposited upon an N-type silicon substrate.
Claim 4
Dependent Claim
23 words
The method of claim 2 wherein said aluminum layer is heated at a temperature between 400° and 500° C. for about 1 hour.
Claim 5
Dependent Claim
27 words
The method of claim 1 wherein said metal layer is cooled at a rate between 5° and 20° C. per second until said metal reaches room temperature.
Claim 6
Dependent Claim
21 words
The method of claim 4 wherein said metal is heated at a temperature of about 400° C. for about 1 hour.
Claim 7
Independent Claim
83 words
A method for forming Schottky barrier diodes comprising the steps of: depositing a layer of aluminum copper alloy upon a substrate of N-type silicon having a doping level less than 8 × 10 16 atoms/cc; depositing a layer of polysilicon semiconductor material upon said metal; heating said metal layer at a temperature between 400° and 500° C. for 1 to 2 hours; and cooling said metal layer at a rate between 5° and 20° C. per second until said metal reaches room temperature.
Claim 8
Independent Claim
83 words
A method for forming Schottky barrier diodes comprising the steps of: depositing a layer of aluminum copper alloy upon a substrate of N-type silicon having a doping level less than 8 × 10 16 atoms/cc; depositing a layer of polysilicon semiconductor material upon said metal; heating said metal layer at a temperature between 400° and 500° C. for 1 to 2 hours; and cooling said metal layer at a rate between 5° and 20° C. per second until said metal reaches room temperature.
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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) | 1979-10-19 | 1980-04-19 | 1980-10-19 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1983-10-19 | 1984-04-19 | 1984-10-19 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1987-10-19 | 1988-04-19 | 1988-10-19 | $7700.00 | Window Closed / Lapsed |