Gallium nitride substrate and manufacturing method of nitride semiconductor crystal

Patent metadata

Field	Value
Publication number	US-9673046-B2
Application number	US-201514740725-A
Country	US
Kind code	B2
Filing date	Jun 16, 2015
Priority date	Dec 17, 2012
Publication date	Jun 6, 2017
Grant date	Jun 6, 2017

Abstract

The invention provides 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 method for manufacturing an M-plane GaN substrate by 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 ammonothermal method, and cutting out the M-plane GaN substrate from the plane-shape GaN crystal.

First claim

The invention claimed is:

1. 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 ammonothermal method, and
cutting out the M-plane GaN substrate from the plane-shape GaN crystal.

2. A method for manufacturing a GaN substrate having an M-plane or a semi-polar plane as a main surface 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 first GaN crystal of which thickness direction is an m-axis direction from the opening of the mask pattern by an ammonothermal method,
cutting out an M-plane seed substrate from the plane-shape first GaN crystal,
growing a second GaN crystal using the M-plane seed substrate as a seed by an ammonothermal method, and
cutting out the GaN substrate having an M-plane or semi-polar plane as a main surface from the second GaN crystal.

3. The method for manufacturing a GaN substrate according to claim 2 , wherein the semi-polar plane is {30-31}, {30-3-1}, {20-21}, {20-2-1}, {10-11}, or {10-1-1}.

4. The method for manufacturing a GaN substrate according to claim 2 , wherein the area of the main surface is 1.0 cm 2 or more.

5. The method for manufacturing a GaN substrate according to claim 4 , wherein averaged basal plane dislocation density in an optional square region sizing 250 μm×250 μm in the main plane is 1×10 6 cm −2 or less.

6. The method for manufacturing a GaN substrate according to claim 5 , wherein the basal plane dislocation density in the main plane is 1×10 4 cm −2 or less.

7. The method for manufacturing a GaN substrate according to claim 6 , wherein the basal plane dislocation density in the main plane is 1×10 2 cm −2 or less.

8. The method for manufacturing a GaN substrate according to claim 6 , wherein the averaged basal plane dislocation density in the optional square region sizing 250 μm×250 μm in the main plane is 1×10 4 cm −2 or less.

9. The method for manufacturing a GaN substrate according to claim 5 , wherein stacking fault density in the main surface is 10 cm −1 or less.

10. A method for manufacturing a GaN substrate having an M-plane or semi-polar plane as a main surface 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 first GaN crystal of which thickness direction is an m-axis direction from the opening of the mask pattern by an ammonothermal method,
cutting out an M-plane first seed substrate from the plane-shape first GaN crystal,
growing a second GaN crystal using the M-plane first seed substrate as a seed by an ammonothermal method,
cutting out a second seed substrate having an M-plane or semi-polar plane as a main surface from the second GaN crystal,
growing a third GaN crystal using the second seed substrate as a seed by a vapor phase growth method, and
cutting out the GaN substrate having an M-plane or semi-polar plane as a main surface from the third GaN crystal.

11. The method for manufacturing a GaN substrate according to claim 10 , wherein the vapor phase growth method is a HVPE method.

12. The method for manufacturing a GaN substrate according to claim 10 , wherein the main surface of the GaN substrate cut out from the third GaN crystal is {10-10}, {30-31}, {30-3-1}, {20-21}, {20-2-1}, {10-11}, or {10-1-1}.

13. The method for manufacturing a GaN substrate according to claim 10 , wherein the area of the main surface of the second seed substrate is 1.0 cm 2 or more.

14. The method for manufacturing a GaN substrate according to claim 10 , wherein averaged basal plane dislocation density in an optional square region sizing 250 μm×250 μm in the main plane of the second seed substrate is 1×10 6 cm −2 or less.

15. The method for manufacturing a GaN substrate according to claim 14 , wherein the basal plane dislocation density in the main plane of the second seed is 1×10 4 cm −2 or less.

16. The method for manufacturing a GaN substrate according to claim 15 , wherein the basal plane dislocation density in the main plane of the second seed is 1×10 2 cm −2 or less.

17. The method for manufacturing a GaN substrate according to claim 15 , wherein the averaged basal plane dislocation density in an optional square region sizing 250 μm×250 μm in the main plane of the second seed is 1×10 4 cm −2 or less.

18. The method for manufacturing a GaN substrate according to claim 14 , wherein stacking fault density in the main surface of the second seed is 10 cm −1 or less.

Assignees

• Mitsubishi Chem Corp

Inventors

• Tsukada Yusuke
• Kubo Shuichi
• Kamada Kazunori
• Fujisawa Hideo
• Ohata Tatsuhiro
• Ikeda Hirotaka
• Matsumoto Hajime
• Mikawa Yutaka

Classifications

• H10P14/3466

  Crystal orientation · CPC title

• H10P14/3442

  N-type · CPC title

• H10P14/3416 Primary

  Nitrides · CPC title

• H10P14/3258

  Crystal orientation · CPC title

• H10P14/3216

  Nitrides · CPC title