Patent US4477311A successfully refreshed from Google Patents.
US4477311A
Expired / Lapsed
US
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Process and apparatus for fabricating a semiconductor device
Assignee: Fujitsu Ltd
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Filing: 1983-12-15
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Granted: 1984-10-16
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Expires: 2003-12-15
Abstract
Abstract MOlecular beam epitaxy (MBE) requires that the surface of a substrate on which a semiconductor layer is formed by MBE be clean. Physical etching damages the substrate, while usual chemical etching damages vacuum pumps and contaminates MBE apparatuses. Hydrogen plasma etching can clean a substrate without damaging a substrate and a vacuum pump and without contaminating an MBE apparatus. Further, by combining MBE with formation of a protective layer without breaking the vacuum used in MBE, diffusion of an impurity in the semiconductor layer formed by MBE can be greatly decreased during a subsequent high-temperature heat treatment.
Inventors
- 👤 Takashi Mimura
- 👤 Kohki Hikosaka
- 👤 Kouichiro Odani
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-27 19:36
CPC Classifications
H; H10; H10P; H10P14/00; H10P14/20; H10P14/22; C; C23; C23C; C23C14/00; C23C14/22; C23C14/56; C30; C30B; C30B23/00; C30B23/02; H01; H01J; H01J37/00; H01J37/32; H10P14/27; H10P14/271; H10P14/29; H10P14/2901; H10P14/2907; H10P14/2911; H10P14/32; H10P14/3202; H10P14/3214; H10P14/3221; H10P14/34; H10P14/3402; H10P14/3414; H10P14/3421; H10P14/60; H10P14/69; H10P14/694; H10P14/6943; H10P14/69433; H10P95/00; H10P95/90; H10P95/904; Y; Y10; Y10S; Y10S148/00; Y10S148/017; Y10S148/022; Y10S148/169; Y10S438/00; Y10S438/913
Claims Analysis
Total Claims: 49
Claim 1
Independent Claim
57 words
A process for fabricating a semiconductor device, comprising the steps of: etching a part of a semiconductor substrate by hydrogen plasma in vacuum; growing a semiconductor layer on the semiconductor substrate at the etched part by molecular beam epitaxy with unbroken vacuum; and forming a protective layer on the surface of the semiconductor layer with unbroken vacuum.
Claim 2
Dependent Claim
57 words
A process for fabricating a semiconductor device, comprising the steps of: etching a part of a semiconductor substrate by hydrogen plasma in vacuum; growing a semiconductor layer on the semiconductor substrate at the etched part by molecular beam epitaxy with unbroken vacuum; and forming a protective layer on the surface of the semiconductor layer with unbroken vacuum.
Claim 3
Dependent Claim
15 words
A process according to claim 1, wherein the semiconductor layer is of a compound semiconductor.
Claim 4
Dependent Claim
14 words
A process according to claim 1, wherein the semiconductor layer is of a GaAs.
Claim 5
Dependent Claim
15 words
A process according to claim 1, wherein the semiconductor substrate is of a compound semiconductor.
Claim 6
Dependent Claim
19 words
A process according to claim 1, wherein at least a part of the semiconductor substrate is composed of AlGaAs.
Claim 7
Dependent Claim
20 words
A process according to claim 1, wherein the etching step is effected to clean the surface of the semiconductor substrate.
Claim 8
Dependent Claim
22 words
A process according to claim 1, wherein the etching step is effected to form a cavity or opening in the semiconductor substrate.
Claim 9
Dependent Claim
28 words
A process according to claim 1, wherein after the step of forming a protective layer, heat treatment is conducted on the semiconductor layer covered with the protective layer.
Claim 10
Dependent Claim
15 words
A process according to claim 8, wherein the protective layer is of an insulating layer.
Claim 11
Dependent Claim
27 words
A process according to claim 8, wherein the protective layer is of one of the group of AlN, SiO 2 , and Si 3 N 4 .
Claim 12
Dependent Claim
19 words
A process according to claim 8, wherein the protective layer is formed by sputtering or by a CVD process.
Claim 13
Dependent Claim
44 words
A process for fabricating a semiconductor device, comprising the steps of: etching a part of a semiconductor substrate by hydrogen plasma in vacuum and then growing a semiconductor layer on the semiconductor substrate at the etched part by molecular beam epitaxy with unbroken vacuum.
Claim 14
Dependent Claim
44 words
A process for fabricating a semiconductor device, comprising the steps of: etching a part of a semiconductor substrate by hydrogen plasma in vacuum and then growing a semiconductor layer on the semiconductor substrate at the etched part by molecular beam epitaxy with unbroken vacuum.
Claim 15
Dependent Claim
15 words
A process according to claim 12, wherein the semiconductor layer is of a compound semiconductor.
Claim 16
Dependent Claim
13 words
A process according to claim 13, wherein the semiconductor layer is of GaAs.
Claim 17
Dependent Claim
15 words
A process according to claim 12, wherein the semiconductor substrate is of a compound semiconductor.
Claim 18
Dependent Claim
19 words
A process according to claim 12, wherein at least a part of the semiconductor substrate is composed of AlGaAs.
Claim 19
Dependent Claim
20 words
A process according to claim 12, wherein the etching step is effected to clean the surface of the semiconductor substrate.
Claim 20
Dependent Claim
22 words
A process according to claim 12, wherein the etching step is effected to form a cavity or opening in the semiconductor substrate.
Claim 21
Dependent Claim
37 words
A process for fabricating a semiconductor device, comprising the steps of: growing a semiconductor layer by molecular beam epitaxy in vacuum and then forming a protective layer on the surface of the semiconductor layer with unbroken vacuum.
Claim 22
Dependent Claim
37 words
A process for fabricating a semiconductor device, comprising the steps of: growing a semiconductor layer by molecular beam epitaxy in vacuum and then forming a protective layer on the surface of the semiconductor layer with unbroken vacuum.
Claim 23
Dependent Claim
28 words
A process according to claim 19, wherein after the step of forming a protective layer, heat treatment is conducted on the semiconductor layer covered with the protective layer.
Claim 24
Dependent Claim
15 words
A process according to claim 19, wherein the semiconductor layer is of a compound semiconductor.
Claim 25
Dependent Claim
13 words
A process according to claim 21, wherein the semiconductor layer is of GaAs.
Claim 26
Dependent Claim
15 words
A process according to claim 19, wherein the protective layer is of an insulating layer.
Claim 27
Dependent Claim
27 words
A process according to claim 19, wherein the protective layer is of one of the group of AlN, SiO 2 , and Si 3 N 4 .
Claim 28
Dependent Claim
19 words
A process according to claim 19, wherein the protective layer is formed by sputtering or by a CVD process.
Claim 29
Independent Claim
100 words
An apparatus for fabricating a semiconductor device, comprising: a first closed chamber for molecular beam epitaxy; a second closed chamber for hydrogen plasma etching communicated with the first chamber; a third closed chamber for forming a protective layer communicated with the first chamber; means for transporting a wafer to be treated among the first, second, and third chambers with unbroken vacuum; a vacuum pump for evacuating one of the first, second, and third chambers; a hydrogen source connected to the second chamber for supplying hydrogen gas; and a gas supply connected to the third chamber for supplying a required gas.
Claim 30
Independent Claim
100 words
An apparatus for fabricating a semiconductor device, comprising: a first closed chamber for molecular beam epitaxy; a second closed chamber for hydrogen plasma etching communicated with the first chamber; a third closed chamber for forming a protective layer communicated with the first chamber; means for transporting a wafer to be treated among the first, second, and third chambers with unbroken vacuum; a vacuum pump for evacuating one of the first, second, and third chambers; a hydrogen source connected to the second chamber for supplying hydrogen gas; and a gas supply connected to the third chamber for supplying a required gas.
Claim 31
Dependent Claim
22 words
An apparatus according to claim 26, wherein the second closed chamber for hydrogen plasma etching is of a parallel plate-shaped electrode type.
Claim 32
Dependent Claim
20 words
An apparatus according to claim 26, wherein the third closed chamber for forming a protective layer is a sputtering chamber.
Claim 33
Dependent Claim
20 words
An apparatus according to claim 26, wherein the third closed chamber for forming a protective layer is a CVD chamber.
Claim 34
Dependent Claim
25 words
An apparatus according to claim 26, wherein a valve is provided between the wafer-transporting means and each of the first, second, and third closed chambers.
Claim 35
Dependent Claim
18 words
An apparatus according to claim 26, wherein the vacuum pump is an ion pump or a cryo pump.
Claim 36
Dependent Claim
23 words
An apparatus according to claim 26, wherein an individual vacuum pump is connected to each of the first, second, and third closed chambers.
Claim 37
Independent Claim
78 words
An apparatus for fabricating a semiconductor device, comprising: a first closed chamber for hydrogen plasma etching; a second closed chamber for molecular beam epitaxy communicated with the first chamber through a gate valve; means for transporting a wafer to be treated between the first and second chambers by external operation with unbroken vacuum; a vacuum pump for evacuating one of the first and second chambers; and a hydrogen source connected to the first chamber for supplying hydrogen gas.
Claim 38
Independent Claim
78 words
An apparatus for fabricating a semiconductor device, comprising: a first closed chamber for hydrogen plasma etching; a second closed chamber for molecular beam epitaxy communicated with the first chamber through a gate valve; means for transporting a wafer to be treated between the first and second chambers by external operation with unbroken vacuum; a vacuum pump for evacuating one of the first and second chambers; and a hydrogen source connected to the first chamber for supplying hydrogen gas.
Claim 39
Dependent Claim
22 words
An apparatus according to claim 33, wherein the first closed chamber for hydrogen plasma etching is of a parallel plate-shaped electrode type.
Claim 40
Dependent Claim
24 words
An apparatus according to claim 33, wherein a valve is provided between the wafer-transporting means and each of the first and second closed chambers.
Claim 41
Dependent Claim
18 words
An apparatus according to claim 33, wherein the vacuum pump is an ion pump or a cryo pump.
Claim 42
Dependent Claim
22 words
An apparatus according to claim 33, wherein an individual vacuum pump is connected to each of the first and second closed chambers.
Claim 43
Independent Claim
71 words
An apparatus for fabricating a semiconductor device, comprising: a first closed chamber for molecular beam epitaxy; a second closed chamber for forming a protective layer communicated with the first closed chamber; means for transporting a wafer to be treated between the first and second chambers; a vacuum pump for evacuating one of the first and second chambers; and a gas source connected to the second chamber for supplying a required gas.
Claim 44
Independent Claim
71 words
An apparatus for fabricating a semiconductor device, comprising: a first closed chamber for molecular beam epitaxy; a second closed chamber for forming a protective layer communicated with the first closed chamber; means for transporting a wafer to be treated between the first and second chambers; a vacuum pump for evacuating one of the first and second chambers; and a gas source connected to the second chamber for supplying a required gas.
Claim 45
Dependent Claim
20 words
An apparatus according to claim 38, wherein the third closed chamber for forming a protective layer is a sputtering chamber.
Claim 46
Dependent Claim
20 words
An apparatus according to claim 38, wherein the third closed chamber for forming a protective layer is a CVD chamber.
Claim 47
Dependent Claim
24 words
An apparatus according to claim 38, wherein a valve is provided between the wafer-transporting means and each of the first and second closed chambers.
Claim 48
Dependent Claim
18 words
An apparatus according to claim 38, wherein the vacuum pump is an ion pump or a cryo pump.
Claim 49
Dependent Claim
22 words
An apparatus according to claim 38, wherein an individual vacuum pump is connected to each of the first and second closed chambers.
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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) | 1987-10-16 | 1988-04-16 | 1988-10-16 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1991-10-16 | 1992-04-16 | 1992-10-16 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1995-10-16 | 1996-04-16 | 1996-10-16 | $7700.00 | Window Closed / Lapsed |