Patent EP0067030A2 successfully refreshed from Google Patents.
US4154632A
Expired / Lapsed
US
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Method of diffusing aluminum into silicon substrate for manufacturing semiconductor device
Assignee: Hitachi Ltd
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Filing: 1978-08-07
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Granted: 1979-05-15
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Expires: 1998-08-07
Abstract
Abstract An aluminum diffusion source layer is formed by vacuum evaporation on a major surface of a silicon substrate. The silicon substrate is heated to form an aluminum-silicon alloy layer, an aluminum doped silicon recrystallization layer and an aluminum diffusion layer. Thereafter, the aluminum-silicon alloy layer is removed from the major surface of the silicon substrate. Drive-in diffusion is performed so as to diffuse, aluminum included in the silicon recrystallization layer and the aluminum diffusion layer, into the silicon substrate. As a result, the aluminum diffusion concentration of 10 16 -10 19 atoms/cm 3 can be obtained.
Inventors
- 👤 Yasuhiro Mochizuki
- 👤 Hiroaki Hachino
- 👤 Yutaka Misawa
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-04 04:30
CPC Classifications
H; H10; H10P; H10P32/00; H10P32/10; H10P32/17; H10P32/171; H10P32/14; H10P32/1408; Y; Y10; Y10S; Y10S148/00; Y10S148/033
Claims Analysis
Total Claims: 4
Claim 1
Independent Claim
108 words
A method of diffusing aluminum into a silicon substrate for manufacturing a semiconductor device, comprising the steps of: (a) forming an aluminum diffusion source layer in a predetermined pattern on a major surface of said silicon substrate; (b) heating said silicon substrate to form an aluminum-silicon alloy layer, an aluminum doped silicon recrystallization layer and an aluminum diffusion layer in accordance with said predetermined pattern; (c) thereafter removing said aluminum-silicon alloy layer from said major surface of said silicon substrate; and (d) heating said silicon substrate to diffuse, aluminum included in said silicon recrystallization layer and said aluminum diffusion layer into said silicon substrate, to a predetermined depth.
Claim 2
Independent Claim
108 words
A method of diffusing aluminum into a silicon substrate for manufacturing a semiconductor device, comprising the steps of: (a) forming an aluminum diffusion source layer in a predetermined pattern on a major surface of said silicon substrate; (b) heating said silicon substrate to form an aluminum-silicon alloy layer, an aluminum doped silicon recrystallization layer and an aluminum diffusion layer in accordance with said predetermined pattern; (c) thereafter removing said aluminum-silicon alloy layer from said major surface of said silicon substrate; and (d) heating said silicon substrate to diffuse, aluminum included in said silicon recrystallization layer and said aluminum diffusion layer into said silicon substrate, to a predetermined depth.
Claim 3
Dependent Claim
24 words
A method as claimed in claim 1, wherein the heat treatment temperature at said step (b) is equal to or lower than 1200° C.
Claim 4
Dependent Claim
27 words
A method as claimed in claim 1, wherein said aluminum diffusion source layer is composed of one selected from the group consisting of aluminum and aluminum-silicon alloy.
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) | 1982-05-14 | 1982-11-13 | 1983-05-15 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1986-05-14 | 1986-11-13 | 1987-05-15 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1990-05-14 | 1990-11-13 | 1991-05-15 | $7700.00 | Window Closed / Lapsed |