US4073676A
Expired / Lapsed
US
⏱️ 0.0 years remaining
GaAs-GaAlAs semiconductor having a periodic corrugation at an interface
Assignee: Hitachi Ltd
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Filing: 1975-02-18
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Granted: 1978-02-14
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Expires: 1995-02-18
Abstract
Abstract A semiconductor device including a GaAs layer having a periodic corrugation on a surface thereof with a GaAsAl layer disposed on the periodic corrugation is formed by contacting a solution consisting of Ga, Al and As heated at a temperature of about 700° C. to the corrugated surface of the GaAs layer and cooling the solution to a temperature of about 670° C. at a cooling rate of 5° C./min. whereby the periodic corrugation is not transfigured so much.
Inventors
- 👤 Kunio Aiki
- 👤 Michiharu Nakamura
- 👤 Junichi Umeda
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-31 02:01
CPC Classifications
H; H10; H10P; H10P50/00; H10P50/60; H10P50/64; H10P50/642; H10P50/646; H10P14/00; H10P14/20; H10P14/26; H10P14/263; H10P14/265; H10P14/29; H10P14/2901; H10P14/2907; H10P14/2911; H10P14/2924; H10P14/2925; H10P14/32; H10P14/3202; H10P14/3214; H10P14/3221; H10P14/34; H10P14/3402; H10P14/3414; H10P14/3421; Y; Y10; Y10S; Y10S148/00; Y10S148/084
Claims Analysis
Total Claims: 12
Claim 1
Independent Claim
101 words
A method for fabricating a semiconductor device having a periodic corrugation at an interface between a GaAs crystal and a GaAlAs layer comprising the steps of: preparing a GaAs crystal; selectively etching the surface of said GaAs crystal, to form a periodic corrugation on the surface of said GaAs crystal; preparing a solution including Ga, Al and As therein; heating said solution to a temperature within a range between 650° C and 750° C; contacting said heated solution onto said periodically corrugated surface of said GaAs crystal; and cooling said solution at a cooling rate between 1° C/min. and 10° C/min.
Claim 2
Independent Claim
101 words
A method for fabricating a semiconductor device having a periodic corrugation at an interface between a GaAs crystal and a GaAlAs layer comprising the steps of: preparing a GaAs crystal; selectively etching the surface of said GaAs crystal, to form a periodic corrugation on the surface of said GaAs crystal; preparing a solution including Ga, Al and As therein; heating said solution to a temperature within a range between 650° C and 750° C; contacting said heated solution onto said periodically corrugated surface of said GaAs crystal; and cooling said solution at a cooling rate between 1° C/min. and 10° C/min.
Claim 3
Dependent Claim
20 words
A method according to claim 1, wherein the cooling rate is within a range between 1° C/min and 5° C/min.
Claim 4
Independent Claim
127 words
A method for fabricating a semiconductor device having a periodic corrugation at an interface between a GaAs crystal and a GaAlAs layer comprising the steps of: preparing a GaAs crystal; selectively etching the surface of said GaAs crystal to form a periodic corrugation on said surface; preparing a solution including Ga, Al and As therein; heating said solution to a temperature higher than a temperature between 650° C and 750° C; cooling said solution at a cooling rate between 1° C/min and 10° C/min; contacting said solution onto the periodically corrugated surface of said GaAs crystal, when the temperature of said solution is within a range between 650° C and 750° C; and further cooling said solution at a cooling rate between 1° C/min and 10° C/min.
Claim 5
Independent Claim
127 words
A method for fabricating a semiconductor device having a periodic corrugation at an interface between a GaAs crystal and a GaAlAs layer comprising the steps of: preparing a GaAs crystal; selectively etching the surface of said GaAs crystal to form a periodic corrugation on said surface; preparing a solution including Ga, Al and As therein; heating said solution to a temperature higher than a temperature between 650° C and 750° C; cooling said solution at a cooling rate between 1° C/min and 10° C/min; contacting said solution onto the periodically corrugated surface of said GaAs crystal, when the temperature of said solution is within a range between 650° C and 750° C; and further cooling said solution at a cooling rate between 1° C/min and 10° C/min.
Claim 6
Dependent Claim
28 words
A method according to claim 3, wherein the cooling rates of said cooling step and further cooling step are within a range between 1° C/min and 5° C/min.
Claim 7
Dependent Claim
23 words
A method according to claim 3, wherein the cooling rates of said cooling step and further cooling step are equal to each other.
Claim 8
Independent Claim
175 words
A method for fabricating a semiconductor device having a periodic corrugation at an interface between a GaAs crystal and a GaAlAs layer comprising the steps of: preparing a plurality of contiguous semiconductor layers which are disposed on a semiconductor body, and which have a surface layer consisting a GaAs crystal; selectively etching the surface of said GaAs crystal to form a periodic corrugation on said surface; preparing a solution including Ga, Al, and As therein; heating said solution to a temperature higher than a temperature between 650° C and 750° C; cooling said solution at a cooling rate between 1° C/min and 10° C/min; contacting said solution onto said periodically corrugated surface of said GaAs crystal, when the temperature of said solution is between 650° C and 750° C; further cooling said solution at a cooling rate between 1° C/min and 10° C/min, whereby a GaAlAs layer is formed on the periodically corrugated surface of said GaAs crystal; and forming first and second metal layers on said semiconductor body and on said GaAlAs layer, respectively.
Claim 9
Independent Claim
175 words
A method for fabricating a semiconductor device having a periodic corrugation at an interface between a GaAs crystal and a GaAlAs layer comprising the steps of: preparing a plurality of contiguous semiconductor layers which are disposed on a semiconductor body, and which have a surface layer consisting a GaAs crystal; selectively etching the surface of said GaAs crystal to form a periodic corrugation on said surface; preparing a solution including Ga, Al, and As therein; heating said solution to a temperature higher than a temperature between 650° C and 750° C; cooling said solution at a cooling rate between 1° C/min and 10° C/min; contacting said solution onto said periodically corrugated surface of said GaAs crystal, when the temperature of said solution is between 650° C and 750° C; further cooling said solution at a cooling rate between 1° C/min and 10° C/min, whereby a GaAlAs layer is formed on the periodically corrugated surface of said GaAs crystal; and forming first and second metal layers on said semiconductor body and on said GaAlAs layer, respectively.
Claim 10
Dependent Claim
34 words
A method according to claim 6, which further comprises the step of forming a second GaAs layer on said GaAlAs layer, and wherein said second metal layer is formed on said second GaAs layer.
Claim 11
Dependent Claim
28 words
A method according to claim 6, wherein the cooling rates of said cooling step and further cooling step are within a range between 1° C/min and 5° C/min.
Claim 12
Dependent Claim
23 words
A method according to claim 6, wherein the cooling rates of said cooling step and further cooling step are equal to each other.
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) | 1981-02-13 | 1981-08-15 | 1982-02-14 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1985-02-13 | 1985-08-15 | 1986-02-14 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1989-02-13 | 1989-08-15 | 1990-02-14 | $7700.00 | Window Closed / Lapsed |