# US 8,771,552 B2 · Group III nitride crystal substrate, epilayer-containing group III nitride crystal substrate, semiconductor device and method of manufacturing the same

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- Number: US 8,771,552 B2
- Document ID: US8771552B2
- Status: Granted
- Kind: B2
- Application number: 12/837,872
- Filed: 2010-07-16
- Published: 2011-01-20
- Granted: 2014-07-08
- Earliest claimed: 2005-06-23
- Assignees: Sumitomo Electric Industries, Ltd.
- Applicants: Keiji Ishibashi; Yusuke Yoshizumi
- Inventors: Keiji Ishibashi; Yusuke Yoshizumi
- Web page: https://patentgrep.com/patent/US8771552B2

## CPC

- C30B 23/025: {characterised by the substrate}
- C30B 29/403: {AIII-nitrides}
- C30B 33/00: After-treatment of single crystals or homogeneous polycrystalline material with defined structure (C30B31/00 takes precedence)
- H10D 62/8503: {Nitride Group III-V materials, e.g. AlN or GaN}
- C30B: SINGLE-CRYSTAL GROWTH (by using ultra-high pressure, e.g. for the formation of diamonds, B01J3/06); UNIDIRECTIONAL SOLIDIFICATION OF EUTECTIC MATERIAL OR UNIDIRECTIONAL DEMIXING OF EUTECTOID MATERIAL; REFINING BY ZONE-MELTING OF MATERIAL (zone-refining of metals or alloys C22B); PRODUCTION OF A HOMOGENEOUS POLYCRYSTALLINE MATERIAL WITH DEFINED STRUCTURE (casting of metals, casting of other substances by the same processes or devices B22D; working of plastics B29; modifying the physical structure of metals or alloys C21D, C22F); SINGLE CRYSTALS OR HOMOGENEOUS POLYCRYSTALLINE MATERIAL WITH DEFINED STRUCTURE; AFTER-TREATMENT OF SINGLE CRYSTALS OR A HOMOGENEOUS POLYCRYSTALLINE MATERIAL WITH DEFINED STRUCTURE (for producing semiconductor devices or parts thereof H10); APPARATUS THEREFOR
- H10D: INORGANIC ELECTRIC SEMICONDUCTOR DEVICES

## Abstract

A group III nitride crystal substrate is provided in which a uniform distortion at a surface layer of the crystal substrate represented by a value of |d1 −d2 |/d2 obtained from a plane spacing d1 at the X-ray penetration depth of 0.3 μm and a plane spacing d2 at the X-ray penetration depth of 5 μm is equal to or lower than 1.9 ×10−3, and the main surface has a plane orientation inclined in the <10-10> direction at an angle equal to or greater than 10° and equal to or smaller than 80° with respect to one of (0001) and (000-1) planes of the crystal substrate. A group III nitride crystal substrate suitable for manufacturing a light emitting device with a blue shift of an emission suppressed, an epilayer-containing group III nitride crystal substrate, a semiconductor device and a method of manufacturing the same can thereby be provided.

## Claims

### Claim 1

A group III nitride crystal substrate, wherein,
a plane spacing of arbitrary specific parallel crystal lattice planes of said crystal substrate being obtained from X-ray diffraction measurement performed with variation of X-ray penetration depth from a main surface of said crystal substrate while X-ray diffraction conditions of said specific parallel crystal lattice planes of said crystal substrate are satisfied,
a uniform distortion at a surface layer of said crystal substrate represented by a value of |d1−d2|/d2 obtained from a plane spacing d1 at said X-ray penetration depth of 0.3 μm and a plane spacing d2 at said X-ray penetration depth of 5 μm is equal to or lower than 1.9×10−3, and
said main surface has a plane orientation inclined in a <10-10> direction at an angle equal to or greater than 10° and equal to or smaller than 80° with respect to one of (0001) and (000-1) planes of said crystal substrate.

### Claim 2 (depends on 1)

The group III nitride crystal substrate according to claim 1, wherein said main surface has a surface roughness Ra of 3 nm or lower.

### Claim 3 (depends on 1)

The group III nitride crystal substrate according to claim 1, wherein said main surface has a plane orientation inclined at an angle falling within ±4° with respect to any of {20-21}, {10-11}, {20-2-1}, and {10-1-1} planes of said crystal substrate.

### Claim 4 (depends on 3)

The group III nitride crystal substrate according to claim 3, wherein said main surface has a plane orientation inclined at an inclination angle having an absolute value of less than 0.1° with respect to any of the {20-21}, {10-11}, {20-2-1}, and {10-1-1} planes of said crystal substrate so as to be substantially parallel thereto.

### Claim 5 (depends on 3)

The group III nitride crystal substrate according to claim 3, wherein said main surface has a plane orientation inclined at an inclination angle having an absolute value of equal to or more than 0.1° and equal to or less than 4° with respect to any of the {20-21}, {10-11}, {20-2-1}, and {10-1-1} planes of said crystal substrate.

### Claim 6 (depends on 1)

The group III nitride crystal substrate according to claim 1, wherein oxygen present at said main surface has a concentration of equal to or more than 2 at. % and equal to or less than 16 at. %.

### Claim 7 (depends on 1)

The group III nitride crystal substrate according to claim 1, wherein a dislocation density at said main surface is equal to or less than 1 ×107 cm−2.

### Claim 8 (depends on 1)

The group III nitride crystal substrate according to claim 1, having a diameter equal to or more than 40 mm and equal to or less than 150 mm.

### Claim 9 (depends on 1)

The group III nitride crystal substrate according to claim 1, wherein said specific parallel crystal lattice planes are not parallel to said main surface, and is parallel to any of (10-10), (10-11), (10-13), (11-20), (11-22), (11-24), (10-1-1), (10-1-3), (11-2-2), and (11-2-4) planes.