US4952527A
Expired / Lapsed
US
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Method of making buffer layers for III-V devices using solid phase epitaxy
Assignee: Massachusetts Institute of Technology
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Filing: 1988-02-19
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Granted: 1990-08-28
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Expires: 2008-02-19
Abstract
Abstract A new III-IV buffer material is described which is produced by low temperature growth of III-V compounds by MBE that has unique and desirable properties, particularly for closely spaced, submicron gate length active III-V semiconductor devices, such as HEMT's, MESFET's and MISFET's. In the case of the III-V material, GaAs, the buffer is grown under arsenic stable growth conditions, at a growth rate of 1 micron/hour, and at a substrate temperature preferably in the range of 150 to about 300 DEG C. The new material is crystalline, highly resistive, optically inactive, and can be overgrown with high quality III-V active layers.
Inventors
- 👤 Arthur R. Calawa
- 👤 Frank W. Smith
- 👤 Michael J. Manfra
- 👤 Chang-Lee Chen
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-05 01:44
CPC Classifications
H; H10; H10D; H10D64/00; H10D64/60; H10D64/66; H10D64/68; H10D64/691; H10D30/00; H10D30/01; H10D30/015; H10D30/051; H10D30/061; H10D30/0612; H10D30/80; H10D30/87; H10D30/877; H10D62/00; H10D62/10; H10D62/17; H10D62/351; H10D62/357; H10D64/01; H10D64/012; H10D64/0124; H10D64/0125; H10D84/00; H10D84/01; H10D84/02; H10D84/05; H10F; H10F30/00; H10F30/10; H10F71/00; H10F71/127; H10P; H10P14/00; H10P14/20; H10P14/22; H10P14/29; H10P14/2901; H10P14/2907; H10P14/2911; H10P14/32; H10P14/3202; H10P14/3214; H10P14/3221; H10P14/34; H10P14/3402; H10P14/3414; H10P14/3421; H01; H01S; H01S5/00; H01S5/02; H01S5/0206; H01S5/0208; H01S5/021; H01S5/026; H01S5/20; H01S5/22; H01S5/223; H10D62/80; H10D62/85; H10D62/852; Y; Y02; Y02E; Y02E10/00; Y02E10/50; Y02E10/544; Y02P; Y02P70/00; Y02P70/50; Y10; Y10S; Y10S148/00; Y10S148/003; Y10S148/025; Y10S148/041; Y10S148/056; Y10S148/154; Y10S438/00; Y10S438/971
Claims Analysis
Total Claims: 14
Claim 1
Independent Claim
103 words
A method of making an intermediate optically inert, electrically insulating crystalline layer of GaAs material on a substrate for growth thereon of high quality crystalline films comprising the steps of: (a) forming in a chamber said crystalline layer of GaAs material by low temperature molecular beam deposition at less than 300° C. of a flux of Ga and As molecular beam specie on a surface of a substrate formed of III-V materials; (b) subjecting said layer to a heat treatment in an ambient containing arsenic; (c) forming a thin stabilizing layer over said heat treated layer to minimize out diffusion of the arsenic.
Claim 2
Independent Claim
103 words
A method of making an intermediate optically inert, electrically insulating crystalline layer of GaAs material on a substrate for growth thereon of high quality crystalline films comprising the steps of: (a) forming in a chamber said crystalline layer of GaAs material by low temperature molecular beam deposition at less than 300° C. of a flux of Ga and As molecular beam specie on a surface of a substrate formed of III-V materials; (b) subjecting said layer to a heat treatment in an ambient containing arsenic; (c) forming a thin stabilizing layer over said heat treated layer to minimize out diffusion of the arsenic.
Claim 3
Dependent Claim
16 words
The method of claim 1 wherein the low temperature is in the range of 150-300° C.
Claim 4
Independent Claim
99 words
A method of making GaAs device on a structure comprising the steps of: (a) forming in a chamber, a crystalline buffer layer of GaAs material by low temperature molecular beam deposition at below 300° C. of a flux of Ga and As materials on a surface of a substrate formed from the group comprising III-V materials; (b) subjecting said layer to a heat treatment in an ambient containing arsenic; (c) forming a thin stabilizing layer of GaAs material over said heat treated layer to minimize out diffusion of the arsenic; (d) forming said GaAs device on said stabilizing layer.
Claim 5
Independent Claim
99 words
A method of making GaAs device on a structure comprising the steps of: (a) forming in a chamber, a crystalline buffer layer of GaAs material by low temperature molecular beam deposition at below 300° C. of a flux of Ga and As materials on a surface of a substrate formed from the group comprising III-V materials; (b) subjecting said layer to a heat treatment in an ambient containing arsenic; (c) forming a thin stabilizing layer of GaAs material over said heat treated layer to minimize out diffusion of the arsenic; (d) forming said GaAs device on said stabilizing layer.
Claim 6
Dependent Claim
12 words
The method of claim 3 wherein the active device is a MESFET.
Claim 7
Dependent Claim
21 words
The method of claim 3 wherein the GaAs device is formed in a crystalline active layer grown on said stabilizing layer.
Claim 8
Dependent Claim
18 words
The method of claim 5 wherein the buffer layer has a resistivity of greater than 10 7 ohm-cm.
Claim 9
Independent Claim
134 words
A method of making an intermediate buffer structure for growth thereon of high quality crystalline electro-optical films comprising the steps of: (a) in a chamber, forming a crystalline buffer layer of thickness greater than 300° Å of material by low temperature molecular beam deposition at less than 300° C. of a flux of Ga and As molecular beam specie on a surface of a substrate, which surface is comprised of materials from the same III-V group of materials as in the buffer layer; (b) subjecting said buffer layer to a heat treatment at less than 900° C. in an ambient containing arsenic; (c) forming a thin stabilizing layer over said heat treated layer to minimize out diffusion of the arsenic; thereby to produce a stable buffer layer which is optically inert and electrically insulating.
Claim 10
Independent Claim
134 words
A method of making an intermediate buffer structure for growth thereon of high quality crystalline electro-optical films comprising the steps of: (a) in a chamber, forming a crystalline buffer layer of thickness greater than 300° Å of material by low temperature molecular beam deposition at less than 300° C. of a flux of Ga and As molecular beam specie on a surface of a substrate, which surface is comprised of materials from the same III-V group of materials as in the buffer layer; (b) subjecting said buffer layer to a heat treatment at less than 900° C. in an ambient containing arsenic; (c) forming a thin stabilizing layer over said heat treated layer to minimize out diffusion of the arsenic; thereby to produce a stable buffer layer which is optically inert and electrically insulating.
Claim 11
Dependent Claim
34 words
The method of claim 1 wherein the low temperature in step (a) is in the range of 150-300° C. and the inert treatment in step (b) occurs at a temperature less than 900° C.
Claim 12
Dependent Claim
13 words
The method of claim 7 wherein the substrate is formed of semi-insulating GaAs.
Claim 13
Independent Claim
89 words
A method of making a III-V device on a substrate comprising the steps of: (a) forming a buffer layer of III-V material by low temperature molecular beam deposition at less than 300° C. of a flux of III-V molecules on said GaAs substrate in a chamber; (b) subjecting said layer to a heat treatment in an ambient containing As; (c) forming a thin stabilizing layer of III-V material over said heat treated layer to minimize out diffusion of the As; (d) forming said III-V device on said stabilizing layer.
Claim 14
Independent Claim
89 words
A method of making a III-V device on a substrate comprising the steps of: (a) forming a buffer layer of III-V material by low temperature molecular beam deposition at less than 300° C. of a flux of III-V molecules on said GaAs substrate in a chamber; (b) subjecting said layer to a heat treatment in an ambient containing As; (c) forming a thin stabilizing layer of III-V material over said heat treated layer to minimize out diffusion of the As; (d) forming said III-V device on said stabilizing layer.
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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) | 1993-08-27 | 1994-02-26 | 1994-08-28 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1997-08-27 | 1998-02-26 | 1998-08-28 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2001-08-27 | 2002-02-26 | 2002-08-28 | $7700.00 | Window Closed / Lapsed |