US4430364A
Expired / Lapsed
US
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Method for forming an aluminum metallic thin film by vapor phase growth on a semiconductor substrate
Assignee: Fujitsu Ltd
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Filing: 1982-03-22
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Granted: 1984-02-07
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Expires: 2002-03-22
Abstract
Abstract An aluminum thin film (14, 24) for semiconductor devices has been heretofore formed by vacuum deposition. However, because the aluminum to be deposited on a semiconductor substrate by vacuum deposition has a directional property of growth, breakage of the resultant aluminum wiring often occurred at a step or sidewall (2a) of the substrate. The present invention provides a method for forming the aluminum thin film (14, 24) by chemical vapor deposition, in which AlCl 3 is reacted with molten aluminum (46) to form AlCl, and the produced AlCl is decomposed into Al and AlCl 3 in the vicinity of the semiconductor substrate, i.e. wafer (47), maintained at a low temperature so as to cause the produced Al to be grown on the wafer (47). In accordance with the present invention, the an aluminum thin film (24) having a uniform thickness can be formed.
Inventors
- 👤 Takashi Ito
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-29 15:16
CPC Classifications
H; H10; H10W; H10W20/00; H10W20/01; H10W20/031; H10W20/062; C; C23; C23C; C23C16/00; C23C16/06; C23C16/08; C23C16/12; H10D; H10D64/00; H10D64/01; H10D64/011; H10D64/0111; H10P; H10P14/00; H10P14/40; H10P14/412
Claims Analysis
Total Claims: 10
Claim 1
Independent Claim
75 words
A method for forming an aluminum thin film by vapor phase growth on a semiconductor substrate having a step, comprising the steps of: decomposing a monovalent aluminum halide into a trivalent aluminum halide and metallic aluminum; and depositing said metallic aluminum on said semiconductor substrate which is maintained at a temperature lower than the melting point of said metallic aluminum and forming a substantially uniform aluminum thin film thereon which covers said step without breaks.
Claim 2
Independent Claim
75 words
A method for forming an aluminum thin film by vapor phase growth on a semiconductor substrate having a step, comprising the steps of: decomposing a monovalent aluminum halide into a trivalent aluminum halide and metallic aluminum; and depositing said metallic aluminum on said semiconductor substrate which is maintained at a temperature lower than the melting point of said metallic aluminum and forming a substantially uniform aluminum thin film thereon which covers said step without breaks.
Claim 3
Dependent Claim
20 words
A method according to claim 1, wherein said metallic aluminum is deposited on said semiconductor substrate in a reduced-pressure atmosphere.
Claim 4
Dependent Claim
22 words
A method according to claim 1, wherein the decomposition reaction of said monovalent aluminum halide is carried out in a hydrogen atmosphere.
Claim 5
Dependent Claim
22 words
A method according to claim 1, 2 or 3 wherein the temperature of said semiconductor substrate is about 400° C. or less.
Claim 6
Dependent Claim
32 words
A method according to claim 1, wherein said decomposition reaction of said monovalent aluminum halide is carried out by reducing the temperature of said monovalent aluminum halide by at least 300° C.
Claim 7
Dependent Claim
23 words
A method according to claim 5, wherein said temperature reduction is effected while said monovalent aluminum halide flows in a horizontal-type reaction tube.
Claim 8
Dependent Claim
40 words
A method according to claim 6, wherein said semiconductor substrate is located in said horizontal-type reaction tube in such a manner that the main plane of said substrate is substantially parallel to the direction of flow of said aluminum halide.
Claim 9
Dependent Claim
21 words
A method according to claim 2, wherein said reduced pressure atmosphere is at a pressure of between 7.6 and 10 Torr.
Claim 10
Dependent Claim
38 words
A method according to claim 2, wherein said monovalent aluminum halide is decomposed at a temperature in the range of 800° C. to 1200° C. and the temperature of said semiconductor substrate is at least 600° C. lower.
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) | 1987-02-06 | 1987-08-08 | 1988-02-07 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1991-02-06 | 1991-08-08 | 1992-02-07 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1995-02-06 | 1995-08-08 | 1996-02-07 | $7700.00 | Window Closed / Lapsed |