US4692991A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method of controlling forward voltage across Schottky diode
Assignee: Signetics Corp
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Filing: 1985-07-19
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Granted: 1987-09-15
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Expires: 2005-07-19
Abstract
Abstract During the deposition of a metallic layer on an N-type semiconductive region to form a Schottky diode in a structure placed in a highly evacuated chamber, at least one selected gas is introduced into the chamber to control the forward voltage across the diode.
Inventors
- 👤 Ronald C. Flowers
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-31 19:32
CPC Classifications
H; H10; H10D; H10D64/00; H10D64/01; H10D64/012; H10D64/0121; Y; Y10; Y10S; Y10S148/00; Y10S148/139; Y10S148/14; Y10S438/00; Y10S438/909
Claims Analysis
Total Claims: 16
Claim 1
Independent Claim
97 words
A method wherein a metallic layer is deposited on an N-type semiconductive region of a structure placed in a highly evacuated chamber to form a rectifying junction between a first portion of the N-type region and a segment of the metallic layer; and an electrical conductor is created to ohmically contact a second portion of the N-type region; characterized by the step of introducing at least one gas into the chamber during the deposition step in order to control the voltage V F between the metallic segment and the conductor when the rectifying junction is forwardly conductive.
Claim 2
Independent Claim
97 words
A method wherein a metallic layer is deposited on an N-type semiconductive region of a structure placed in a highly evacuated chamber to form a rectifying junction between a first portion of the N-type region and a segment of the metallic layer; and an electrical conductor is created to ohmically contact a second portion of the N-type region; characterized by the step of introducing at least one gas into the chamber during the deposition step in order to control the voltage V F between the metallic segment and the conductor when the rectifying junction is forwardly conductive.
Claim 3
Dependent Claim
30 words
A method as in claim 1 characterized by the step of evacuating the chamber to a pressure no greater than 10 -5 torr before the gas introduction and deposition steps.
Claim 4
Dependent Claim
19 words
A method as in claim 2 characterized in that the gas introduction step is started before the deposition step.
Claim 5
Dependent Claim
29 words
A method as in claim 3 characterized in that the gas introduction step is performed during deposition of at least the first few atomic monolayers of the metallic layer.
Claim 6
Dependent Claim
50 words
A method as in claim 3 wherein: the metallic layer consists substantially of aluminum; and the N-type region consists substantially of doped monocrystalline silicon; characterized in that V F decreases at constant current through the rectifying junction where the gas introduction step consists substantially of introducing nitrogen into the chamber.
Claim 7
Dependent Claim
28 words
A method as in claim 1 characterized in that the gas introduction step consists substantially of introducing at least one of oxygen, nitrogen, and argon into the chamber.
Claim 8
Dependent Claim
26 words
A method as in claim 6 characterized in that the pressure in the chamber is on the order of 10 -6 torr during the deposition step.
Claim 9
Dependent Claim
82 words
A method as in claim 3 wherein: the second portion is more highly doped than the first portion; the deposition step comprises evaporatively depositing atoms of the metallic layer on the N-type region; and the metallic layer is selectively etched to divide it into a plurality of separated parts of which two are the segment and the conductor; characterized in that the metallic layer comprises at least one of aluminum, copper, gold, silver, nickel, palladium, platinum, chromium, molybdenum, tungsten, titanium, and iridium.
Claim 10
Dependent Claim
52 words
A method as in claim 3 wherein: the metallic layer consists substantially of aluminum; and the N-type region consists substantially of doped monocrystalline silicon; characterized in that V F increases at constant current through the rectifying junction where the gas introduction step consists substantially of introducing oxygen or argon into the chamber.
Claim 11
Independent Claim
104 words
A method wherein a metallic layer consisting substantially of aluminum is physically deposited on an N-type semiconductive region of a structure placed in a highly evacuated chamber to form a rectifying junction between a first portion of the N-type region and a segment of the layer; and an electrical conductor is created to ohmically contact a second portion of the N-type region; characterized by the step of introducing at least one gas into the chamber during at least the beginning of deposition step in order to control the voltage V F between the segment and the conductor when the rectifying junction is forwardly conductive.
Claim 12
Independent Claim
104 words
A method wherein a metallic layer consisting substantially of aluminum is physically deposited on an N-type semiconductive region of a structure placed in a highly evacuated chamber to form a rectifying junction between a first portion of the N-type region and a segment of the layer; and an electrical conductor is created to ohmically contact a second portion of the N-type region; characterized by the step of introducing at least one gas into the chamber during at least the beginning of deposition step in order to control the voltage V F between the segment and the conductor when the rectifying junction is forwardly conductive.
Claim 13
Dependent Claim
45 words
A method as in claim 10 wherein the deposition step comprises evaporatively depositing atoms of the layer on the N-type region, characterized by the step of evacuating the chamber to a pressure no greater than 10 -5 torr before the gas introduction and deposition steps.
Claim 14
Dependent Claim
42 words
A method as in claim 11 wherein the N-type region consists substantially of doped monocrystalline silicon, characterized in that V F decreases at constant current through the rectifying junction where the gas introduction step consists substantially of introducing nitrogen into the chamber.
Claim 15
Dependent Claim
28 words
A method as in claim 11 characterized in that the gas introduction step consists substantially of introducing at least one of oxygen, nitrogen, and argon into the chamber.
Claim 16
Dependent Claim
44 words
A method as in claim 11 wherein the N-type region consists substantially of doped monocrystalline silicon, characterized in that V F increases at constant current through the rectifying junction where the gas introduction step consists substantially of introducing oxygen or argon into the chamber.
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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) | 1990-09-14 | 1991-03-16 | 1991-09-15 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1994-09-14 | 1995-03-16 | 1995-09-15 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1998-09-14 | 1999-03-16 | 1999-09-15 | $7700.00 | Window Closed / Lapsed |