US6096130A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method of crystal growth of a GaN layer over a GaAs substrate
Assignee: NEC Corp
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Filing: 1997-03-21
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Granted: 2000-08-01
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Expires: 2017-03-21
Abstract
Abstract A method of crystal growth of a GaN layer with an extremely high surface planarity over a GaAs substrate is provided, wherein a GaAs substrate is heated to a temperature in the range of 600° C. to 700° C. without supplying any group-V element including arsenic to form a Ga-rich surface on the GaAs substrate, before a first source material including N and a second source material including Ga are supplied along with a carrier gas onto a surface of the GaAs substrate to form a GaN layer over the GaAs substrate.
Inventors
- 👤 Akitaka Kimura
- 👤 Haruo Sunakawa
- 👤 Masaaki Nido
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-01 21:10
CPC Classifications
C; C30; C30B; C30B25/00; C30B25/02; C30B29/00; C30B29/10; C30B29/40; C30B29/403; C30B29/406; H; H10; H10P; H10P14/00; H10P14/20; H10P14/203; H10P14/24; H10P14/29; H10P14/2901; H10P14/2907; H10P14/2911; H10P14/2926; H10P14/32; H10P14/3202; H10P14/3214; H10P14/3216; H10P14/3221; H10P14/34; H10P14/3402; H10P14/3414; H10P14/3416; H10P14/36; H10P14/3602
Claims Analysis
Total Claims: 22
Claim 1
Independent Claim
93 words
A method of crystal growth of a GaN layer with an extremely high surface planarity over a GaAs substrate, wherein a GaAs substrate is heated to a temperature in the range of 600° C. to 700° C. without supplying any group-V element source material including arsenic to thereby form a Ga-rich surface on the GaAs substrate, before a first source material including N and a second source material including Ga are supplied along with a carrier gas onto a surface of the GaAs substrate to form a GaN layer over the GaAs substrate.
Claim 2
Independent Claim
93 words
A method of crystal growth of a GaN layer with an extremely high surface planarity over a GaAs substrate, wherein a GaAs substrate is heated to a temperature in the range of 600° C. to 700° C. without supplying any group-V element source material including arsenic to thereby form a Ga-rich surface on the GaAs substrate, before a first source material including N and a second source material including Ga are supplied along with a carrier gas onto a surface of the GaAs substrate to form a GaN layer over the GaAs substrate.
Claim 3
Dependent Claim
25 words
The method as claimed in claim 1, wherein a GaAs buffer layer is further formed over the GaAs substrate before the GaAs substrate is heated.
Claim 4
Dependent Claim
47 words
The method as claimed in claim 1, wherein only a group-V source material including N is supplied along with the carrier gas onto a surface of the GaAs substrate for nitrization of a surface of the GaAs substrate before the first and second source materials are supplied.
Claim 5
Dependent Claim
17 words
The method as claimed in claim 1, wherein the GaAs substrate is heated in a reduction atmosphere.
Claim 6
Dependent Claim
19 words
The method as claimed in claim 1, wherein the GaN layer is grown by a hydride vapor phase epitaxy.
Claim 7
Dependent Claim
32 words
The method as claimed in claim 1, wherein the GaN layer is grown at a low temperature for an initial period and then grown at a high temperature for a later period.
Claim 8
Dependent Claim
24 words
The method as claimed in claim 1, wherein the GaAs substrate has a surface slightly tilted from a (100) surface toward a [111]B direction.
Claim 9
Dependent Claim
22 words
The method as claimed in claim 7, wherein the GaAs substrate is doped with CrO at a concentration of 0.33 weight ppm.
Claim 10
Dependent Claim
25 words
The method as claimed in claim 1, wherein the GaAs substrate is heated to a temperature in the range of 620° C. to 650° C.
Claim 11
Independent Claim
145 words
A method of crystal growth of a GaN layer with an extremely high surface planarity over a GaAs substrate, said method comprising the steps of: subjecting, with only hydrogen being supplied, a GaAs substrate to a heat treatment at a first temperature in the range of 630° C. to 640° C. to remove any oxide film from a surface of the GaAs substrate and form a Ga-rich surface on the GaAs substrate; dropping the temperature of the GaAs substrate to a second temperature lower than the first temperature and supplying GaCl and ammonia along with a nitrogen carrier gas onto the Ga-rich surface on the GaAs substrate to grow a thin GaN buffer layer over the Ga-rich surface; and raising the temperature of the GaAs substrate to a third temperature higher than the first temperature and growing a GaN layer over the GaN buffer layer.
Claim 12
Independent Claim
145 words
A method of crystal growth of a GaN layer with an extremely high surface planarity over a GaAs substrate, said method comprising the steps of: subjecting, with only hydrogen being supplied, a GaAs substrate to a heat treatment at a first temperature in the range of 630° C. to 640° C. to remove any oxide film from a surface of the GaAs substrate and form a Ga-rich surface on the GaAs substrate; dropping the temperature of the GaAs substrate to a second temperature lower than the first temperature and supplying GaCl and ammonia along with a nitrogen carrier gas onto the Ga-rich surface on the GaAs substrate to grow a thin GaN buffer layer over the Ga-rich surface; and raising the temperature of the GaAs substrate to a third temperature higher than the first temperature and growing a GaN layer over the GaN buffer layer.
Claim 13
Dependent Claim
21 words
The method as claimed in claim 10, wherein said second temperature is 485° C. and the third temperature is 700° C.
Claim 14
Independent Claim
143 words
A method of crystal growth of a GaN layer with an extremely high surface planarity over a GaAs substrate, said method comprising the steps of: forming a GaAs buffer layer over a GaAs substrate; subjecting, with only hydrogen being supplied, a GaAs substrate to a heat treatment at a first temperature in the range of 630° C. to 640° C. to form a Ga-rich surface on the GaAs buffer layer; dropping the temperature of the GaAs substrate to a second temperature lower than the first temperature and supplying GaCl and ammonia along with a nitrogen carrier gas onto the Ga-rich surface on the GaAs substrate to grow a thin GaN buffer layer over the Ga-rich surface; and raising the temperature of the GaAs substrate to a third temperature higher than the first temperature and growing a GaN layer over the GaN buffer layer.
Claim 15
Independent Claim
143 words
A method of crystal growth of a GaN layer with an extremely high surface planarity over a GaAs substrate, said method comprising the steps of: forming a GaAs buffer layer over a GaAs substrate; subjecting, with only hydrogen being supplied, a GaAs substrate to a heat treatment at a first temperature in the range of 630° C. to 640° C. to form a Ga-rich surface on the GaAs buffer layer; dropping the temperature of the GaAs substrate to a second temperature lower than the first temperature and supplying GaCl and ammonia along with a nitrogen carrier gas onto the Ga-rich surface on the GaAs substrate to grow a thin GaN buffer layer over the Ga-rich surface; and raising the temperature of the GaAs substrate to a third temperature higher than the first temperature and growing a GaN layer over the GaN buffer layer.
Claim 16
Dependent Claim
21 words
The method as claimed in claim 12, wherein said second temperature is 485° C. and the third temperature is 700° C.
Claim 17
Independent Claim
168 words
A method of crystal growth of a GaN layer with an extremely high surface planarity over a GaAs substrate, said method comprising the steps of: subjecting, with only hydrogen being supplied, a GaAs substrate to a heat treatment at a first temperature in the range of 630° C. to 640° C. to remove any oxide film from a surface of the GaAs substrate and form a Ga-rich surface on the GaAs substrate; dropping the temperature of the GaAs substrate to a second temperature lower than the first temperature and supplying an ammonia containing carrier gas onto the Ga-rich surface on the GaAs substrate for nitrization of a surface of the GaAs substrate; supplying GaCl and ammonia along with a nitrogen carrier gas onto the Ga-rich surface on the GaAs substrate to grow a thin GaN buffer layer over the Ga-rich surface; and raising the temperature of the GaAs substrate to a third temperature higher than the first temperature and growing a GaN layer over the GaN buffer layer.
Claim 18
Independent Claim
168 words
A method of crystal growth of a GaN layer with an extremely high surface planarity over a GaAs substrate, said method comprising the steps of: subjecting, with only hydrogen being supplied, a GaAs substrate to a heat treatment at a first temperature in the range of 630° C. to 640° C. to remove any oxide film from a surface of the GaAs substrate and form a Ga-rich surface on the GaAs substrate; dropping the temperature of the GaAs substrate to a second temperature lower than the first temperature and supplying an ammonia containing carrier gas onto the Ga-rich surface on the GaAs substrate for nitrization of a surface of the GaAs substrate; supplying GaCl and ammonia along with a nitrogen carrier gas onto the Ga-rich surface on the GaAs substrate to grow a thin GaN buffer layer over the Ga-rich surface; and raising the temperature of the GaAs substrate to a third temperature higher than the first temperature and growing a GaN layer over the GaN buffer layer.
Claim 19
Dependent Claim
21 words
The method as claimed in claim 14, wherein said second temperature is 485° C. and the third temperature is 700° C.
Claim 20
Independent Claim
178 words
A method of crystal growth of a GaN layer with an extremely high surface planarity over a GaAs substrate, said method comprising the steps of: forming a GaAs buffer layer over a GaAs substrate; subjecting, with only hydrogen being supplied, a GaAs substrate to a heat treatment at a first temperature in the range of 630° C. to 640° C. to remove any oxide film from a surface of the GaAs substrate and form a Ga-rich surface on the GaAs substrate; dropping the temperature of the GaAs substrate to a second temperature lower than the first temperature and supplying an ammonia containing carrier gas onto the Ga-rich surface on the GaAs substrate for nitrization of a surface of the GaAs substrate; supplying GaCl and ammonia along with a nitrogen carrier gas onto the Ga-rich surface on the GaAs substrate to grow a thin GaN buffer layer over the Ga-rich surface; and raising the temperature of the GaAs substrate to a third temperature higher than the first temperature and growing of a GaN layer over the GaN buffer layer.
Claim 21
Independent Claim
178 words
A method of crystal growth of a GaN layer with an extremely high surface planarity over a GaAs substrate, said method comprising the steps of: forming a GaAs buffer layer over a GaAs substrate; subjecting, with only hydrogen being supplied, a GaAs substrate to a heat treatment at a first temperature in the range of 630° C. to 640° C. to remove any oxide film from a surface of the GaAs substrate and form a Ga-rich surface on the GaAs substrate; dropping the temperature of the GaAs substrate to a second temperature lower than the first temperature and supplying an ammonia containing carrier gas onto the Ga-rich surface on the GaAs substrate for nitrization of a surface of the GaAs substrate; supplying GaCl and ammonia along with a nitrogen carrier gas onto the Ga-rich surface on the GaAs substrate to grow a thin GaN buffer layer over the Ga-rich surface; and raising the temperature of the GaAs substrate to a third temperature higher than the first temperature and growing of a GaN layer over the GaN buffer layer.
Claim 22
Dependent Claim
21 words
The method as claimed in claim 16, wherein said second temperature is 485° C. and the third temperature is 700° C.
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) | 2003-08-01 | 2004-01-31 | 2004-08-01 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2007-08-01 | 2008-01-31 | 2008-08-01 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2011-08-01 | 2012-01-31 | 2012-08-01 | $7700.00 | Window Closed / Lapsed |