GALLIUM NITRIDE SUBSTRATE AND MANUFACTURING METHOD OF NITRIDE SEMICONDUCTOR CRYSTAL

• US 20170200789A1
• Filed: 03/29/2017
• Published: 07/13/2017
• Est. Priority Date: 12/17/2012
• Status: Active Grant

• Current Assignee: Mitsubishi Chemical Corporation (Mitsubishi Chemical Group Corp.)
• Original Assignee: Mitsubishi Chemical Corporation (Mitsubishi Chemical Group Corp.)
• Inventors: TSUKADA, Yusuke, KUBO, Shuichi, KAMADA, Kazunori, FUJISAWA, Hideo, OHATA, Tatsuhiro, IKEDA, Hirotaka, MATSUMOTO, Hajime, MlKAWA, Yutaka
• Granted Patent: US 10,734,485 B2
• Time in Patent Office: Days
• CPC Class Codes: C30B 25/00 Single-crystal growth by chemical reaction of reactive gases, e.g. chemical vapour-deposition growth
• CPC Class Codes: C30B 25/02 Epitaxial-layer growth
• CPC Class Codes: C30B 25/20 the substrate being of the same materials as the epitaxial layer
• CPC Class Codes: C30B 29/406 Gallium nitride
• CPC Class Codes: H01L 21/02389 Nitrides
• CPC Class Codes: H01L 21/02433 Crystal orientation
• CPC Class Codes: H01L 21/02458 Nitrides
• CPC Class Codes: H01L 21/02516 Crystal orientation
• CPC Class Codes: H01L 21/0254 Nitrides
• CPC Class Codes: H01L 21/02576 N-type
• CPC Class Codes: H01L 21/02609 Crystal orientation
• CPC Class Codes: H01L 21/0262 Reduction or decomposition of gaseous compounds, e.g. CVD
• CPC Class Codes: H01L 21/02639 Preparation of substrate for selective deposition
• CPC Class Codes: H01L 29/2003 Nitride compounds
• CPC Class Codes: H01L 29/32 the imperfections being within the semiconductor body
• CPC Class Codes: H01L 33/007 comprising nitride compounds
• CPC Class Codes: H01L 33/12 with a stress relaxation structure, e.g. buffer layer
• CPC Class Codes: H01L 33/32 containing nitrogen

Abstract

The main purpose of the present invention is to provide: a nonpolar or semipolar GaN substrate, in which a nitride semiconductor crystal having a low stacking fault density can be epitaxially grown on the main surface of the substrate, and a technique required for the production of the substrate.

This invention provides: a method for manufacturing an M-plane GaN substrate comprising;

• • forming a mask pattern having a line-shaped opening parallel to an a-axis of a C-plane GaN substrate on an N-polar plane of the C-plane GaN substrate,
  • growing a plane-shape GaN crystal of which thickness direction is an m-axis direction from the opening of the mask pattern by an ammonotharmal method, and
  • cutting out the M-plane GaN substrate from the plane-shape GaN crystal.

Claims

1. A gallium nitride substrate comprising a first main surface and a second main surface opposite thereto, wherein the first main surface has a normal vector of which angle to the <

10−

10>

direction is from 0 to 10°

,

an n-type carrier density is 3×

10¹⁸ cm<sup>−

3</sup> or more, and

a stacking fault density in the first main surface is 50 cm<sup>−

1</sup> or less.

2. The gallium nitride substrate according to claim 1, wherein the stacking fault density is 10 cm⁻

1 or less.

3. The gallium nitride substrate according to claim 1, wherein the n-type carrier density is 4×

10¹⁸ cm<sup>−

3</sup> or more.

4. The gallium nitride substrate according to claim 1, wherein the n-type carrier density is 5×

10¹⁸ cm<sup>−

3</sup> or more.

5. The gallium nitride substrate according to claim 1, wherein a variation of oxygen concentration in a plane parallel to the first main surface is less than five-fold.

6. The gallium nitride substrate according to claim 1, wherein an oxygen concentration is 4×

10¹⁸ cm<sup>−

3</sup> or more.

7. The gallium nitride substrate according to claim 1, wherein an angle between a growth direction of a gallium nitride crystal constituting the substrate and the <

10−

10>

direction of the crystal is from 0 to 10°

.

14. A method for manufacturing a semiconductor device, comprising epitaxially growing a nitride semiconductor on the gallium nitride substrate according to claim 1.

15. The method according to claim 14, wherein the semiconductor device is a semiconductor light-emitting device.

18. A GaN layer bonded substrate, comprising a structure in which a GaN layer separated from the gallium nitride substrate according to claim 1 is bonded to a different-composition substrate.

8. A gallium nitride substrate comprising a first main surface and a second main surface opposite thereto, wherein the first main surface has a normal vector of which angle to the <

10−

10>

direction is from 0 to 10°

,

an oxygen concentration is 4×

10¹⁸ cm<sup>−

3</sup> or more, and

a stacking fault density in the first main surface is 50 cm<sup>−

1</sup> or less.

9. The gallium nitride substrate according to claim 8, wherein the stacking fault density is 10 cm⁻

1 or less.

10. The gallium nitride substrate according to claim 8, wherein a variation of oxygen concentration in a plane parallel to the first main surface is less than five-fold.

11. The gallium nitride substrate according to claim 8, wherein the n-type carrier density is 4×

10¹⁸ cm<sup>−

3</sup> or more.

12. The gallium nitride substrate according to claim 8, wherein the n-type carrier density is 5×

10¹⁸ cm<sup>−

3</sup> or more.

13. The gallium nitride substrate according to claim 8, wherein an angle between a growth direction of a gallium nitride crystal constituting the substrate and the <

10−

10>

direction of the crystal is from 0 to 10°

.

16. A method for manufacturing a semiconductor device, comprising epitaxially growing a nitride semiconductor on the gallium nitride substrate according to claim 8.

17. The manufacturing method according to claim 16, wherein the semiconductor device is a semiconductor light-emitting device.

19. A GaN layer bonded substrate, comprising a structure in which a GaN layer separated from the gallium nitride substrate according to claim 8 is bonded to a different-composition substrate.