Patent US3645808A successfully refreshed from Google Patents.
US3645808A
Expired / Lapsed
US
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Method for fabricating a semiconductor-integrated circuit
Assignee: Hitachi Ltd
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Filing: 1968-04-24
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Granted: 1972-02-29
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Expires: 1988-04-24
Abstract
Abstract A method for selectively diffusing gold into a silicon substrate, wherein a plurality of circuit elements spaced from each other are formed on a surface portion of the substrate and a gold layer, not covering the PN-junction exposed at the surface thereof, is deposited on the surface of a specific circuit element which is desired to have a high-switching speed and then said gold is subjected to thermal treatment so that said deposited gold may be diffused into said specific circuit element.
Inventors
- 👤 Takamitsu Kamiyama
- 👤 Michiyoshi Maki
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-27 13:15
CPC Classifications
H; H10; H10D; H10D84/00; H10D84/01; H10P; H10P32/00; H10P32/10; H10P32/17; H10P32/171; H10P32/18; H10P95/00; Y; Y10; Y10S; Y10S148/00; Y10S148/062; Y10S438/00; Y10S438/914; Y10S438/917
Claims Analysis
Total Claims: 7
Claim 1
Independent Claim
24 words
A method according to claim 6 in which the material preventing gold diffusion is one selected from a group consisting of phosphorus and antimony.
Claim 2
Dependent Claim
28 words
A method according to claim 1 in which the material of the diffusion region contains more than 1019 atoms per cubic centimeter of the material preventing gold diffusion.
Claim 3
Dependent Claim
23 words
A method according to claim 1 in which the semiconductor substrate is silicon and the circuit element is a transistor or a diode.
Claim 4
Dependent Claim
41 words
A method according to claim 1 in which said thermal treatment is carried out for a period of time in the range of 1 minute to 10 minutes and at a temperature in the range from 900* centigrade to 1,100* centigrade.
Claim 5
Dependent Claim
16 words
A method according to claim 5 in which the thermal treatment is performed for 2.5 minutes.
Claim 6
Dependent Claim
22 words
A method according to claim 6, wherein the thermal treatment is performed at a temperature of from about 1,000* to 1,100* C.
Claim 7
Dependent Claim
54 words
A method according to claim 1, in which thE material preventing gold diffusion is phosphorus or antimony and has a concentration of more than 1019 atoms per cubic centimeter in said diffusion region and said thermal treatment is performed for 1 minute to 10 minutes at a temperature of from 900* to 1,100* C.
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) | 1975-02-28 | 1975-08-30 | 1976-02-29 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1979-02-28 | 1979-08-30 | 1980-02-29 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1983-02-28 | 1983-08-30 | 1984-02-29 | $7700.00 | Window Closed / Lapsed |