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US5656832A
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Semiconductor heterojunction device with ALN buffer layer of 3nm-10nm average film thickness
Assignee: Toshiba Corp
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Filing: 1995-03-08
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Granted: 1997-08-12
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Expires: 2015-03-08
Abstract
Abstract A semiconductor device comprises a single crystal substrate, a nucleus formation buffer layer formed on the single crystal substrate, and a lamination layer including a plurality of Al 1-x-y Ga x In y N (0≦x≦1, 0≦y≦1, x+y≦1) layers laminated above the nucleus formation buffer layer. The nucleus formation buffer layer is formed of Al 1-s-t Ga s In t N (0≦s ≦1, 0≦t≦1, s+t≦1) and is formed on a surface of the substrate such that the nucleus formation buffer layer has a number of pinholes for control of polarity and formation of nuclei. A method of fabricating a semiconductor device comprises the steps of: forming, above an Al 1-x-y Ga x In y N (0≦x≦1, 0≦y≦1, x+y≦1) semiconductor layer doped with a p-type dopant, a cap layer for preventing evaporation of a constituent element of the semiconductor layer, the cap layer being formed of one of AlN in which a p-type dopant is added and Al 2 O 3 , subjecting the semiconductor layer to heat treatment, and removing at least a part of the cap layer.
Inventors
- 👤 Yasuo Ohba
- 👤 Ako Hatano
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-07 08:13
CPC Classifications
H; H10; H10H; H10H20/00; H10H20/80; H10H20/81; H10H20/822; H10H20/824; H10H20/825; H01; H01S; H01S5/00; H01S5/04; H01S5/042; H01S5/0425; H01S5/04252; H01S5/30; H01S5/32; H01S5/323; H01S5/32308; H01S5/32341; H10D; H10D62/00; H10D62/80; H10D62/82; H10D62/824; H10D62/85; H10D62/852; H10H20/01; H10H20/011; H10H20/013; H10H20/0133; H10H20/01335; H01S5/02; H01S5/0206; H01S5/0208; H01S5/04256; H01S5/04257
Claims Analysis
Total Claims: 13
Claim 1
Independent Claim
106 words
A semiconductor device comprising: a single crystal substrate; a nucleus formation buffer layer formed on said single crystal substrate; and a lamination layer including a plurality of Al 1-x-y Ga x In y N (0≦x≦1, 0≦y≦, x+y≦1) layers laminated above said nucleus formation buffer layer, wherein said nucleus formation buffer layer is formed of AlN and formed on a surface of said substrate with an average film thickness of 3 nm to 10 nm such that said nucleus formation buffer layer has a number of pinholes for control of polarity and formation of nuclei, said pinholes being formed among loosely formed small crystals of said AlN.
Claim 2
Dependent Claim
106 words
A semiconductor device comprising: a single crystal substrate; a nucleus formation buffer layer formed on said single crystal substrate; and a lamination layer including a plurality of Al 1-x-y Ga x In y N (0≦x≦1, 0≦y≦, x+y≦1) layers laminated above said nucleus formation buffer layer, wherein said nucleus formation buffer layer is formed of AlN and formed on a surface of said substrate with an average film thickness of 3 nm to 10 nm such that said nucleus formation buffer layer has a number of pinholes for control of polarity and formation of nuclei, said pinholes being formed among loosely formed small crystals of said AlN.
Claim 3
Dependent Claim
23 words
The semiconductor device according to claim 1, wherein said nucleus formation buffer layer is a layer grown at 350° C. to 800° C.
Claim 4
Dependent Claim
37 words
The semiconductor device according to claim 1, wherein a temperature raising process after the formation of said nucleus formation buffer layer and before the start of formation of said lamination layer is performed in an ammonia-free atmosphere.
Claim 5
Dependent Claim
21 words
The semiconductor device according to claim 3, wherein said lamination layer is formed in an atmosphere at 70 Torr or below.
Claim 6
Dependent Claim
16 words
The semiconductor device according to claim 1, wherein said single crystal substrate is formed of sapphire.
Claim 7
Dependent Claim
26 words
The semiconductor device according to claim 5, wherein a surface to be treated of said single crystal substrate is a C face of the sapphire substrate.
Claim 8
Dependent Claim
36 words
The semiconductor device according to claim 5, wherein a surface to be treated of the single crystal substrate is inclined by 0.5° to 10° from a C face to an A face of the sapphire substrate.
Claim 9
Dependent Claim
31 words
The semiconductor device according to claim 1, wherein said lamination layer includes a light emitting diode of a double-hetero structure having an active layer sandwiched by p-type and n-type cladding layers.
Claim 10
Dependent Claim
47 words
The semiconductor device according to claim 1, further comprising a thermal distortion reducing buffer layer formed of Al 1-u-v Ga u In v N (0≦u≦1, 0≦v≦1, u+v≦1) on said nucleus formation buffer layer, said thermal distortion reducing buffer layer being thicker than said nucleus formation buffer layer.
Claim 11
Dependent Claim
22 words
The semiconductor device according to claim 9, wherein said thermal distortion reducing buffer layer is grown at 350° C. to 800° C.
Claim 12
Dependent Claim
32 words
The semiconductor device according to claim 9, wherein said Al 1-u-v Ga u In v N (0≦u≦1, 0≦v≦1, u+v≦1) constituting said thermal distortion reducing buffer layer is one of InN and GaInN.
Claim 13
Dependent Claim
34 words
The semiconductor device according to claim 11, further comprising a cap layer for preventing evaporation of In contained in said buffer layer, said cap layer being formed on said thermal distortion reducing buffer layer.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
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| 3.5 Years (Year 4) | 2000-08-11 | 2001-02-10 | 2001-08-12 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2004-08-11 | 2005-02-10 | 2005-08-12 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2008-08-11 | 2009-02-10 | 2009-08-12 | $7700.00 | Window Closed / Lapsed |