Method of manufacturing gallium oxide substrate and polishing slurry for gallium oxide substrate

Patent metadata

Field	Value
Publication number	US-12187918-B2
Application number	US-202117481256-A
Country	US
Kind code	B2
Filing date	Sep 21, 2021
Priority date	Mar 27, 2019
Publication date	Jan 7, 2025
Grant date	Jan 7, 2025

Abstract

A method of manufacturing a gallium oxide substrate includes polishing the gallium oxide substrate with a polishing slurry, wherein the polishing slurry contains manganese dioxide particles and water.

First claim

What is claimed is:

1. A method of manufacturing a gallium oxide substrate, the method comprising:
polishing a single crystal gallium oxide substrate with a polishing slurry,
wherein the polishing slurry contains manganese dioxide particles and water, and
wherein said polishing is performed at a polishing speed of at least 7.2 μm/h.

2. The method of claim 1 , wherein an amount of the manganese dioxide particles contained in the polishing slurry is 0.01% by mass or more and 50% by mass or less.

3. The method of claim 1 , wherein a pH of the polishing slurry is either 1 or more and 3 or less, or 7 or more and 14 or less.

4. The method of claim 1 , wherein a diameter at which a cumulative volume is 50% in a particle size distribution of the manganese dioxide particles measured by a dynamic light scattering method is 1 nm or more and 2000 nm or less.

5. The method of claim 1 , further comprising cleaning the single crystal gallium oxide substrate with a cleaning liquid after the polishing of the single crystal gallium oxide substrate.

6. The method of claim 5 , wherein the cleaning liquid contains ascorbic acid, erythorbic acid, or a combination of both, and has a pH of 6 or less.

7. The method of claim 5 , wherein the cleaning liquid contains sulfuric acid, hydrochloric acid, or a combination of both, and contains hydrogen peroxide.

8. The method of claim 1 , wherein the single crystal gallium oxide substrate is a β-Ga 2 O 3 single crystal substrate.

9. The method of claim 8 , wherein the polishing comprises polishing the (001) plane of the β-Ga 2 O 3 single crystal substrate.

10. The method of claim 1 , wherein an amount of the manganese dioxide particles contained in the polishing slurry is 1% by mass or more and 20% by mass or less.

11. The method of claim 10 , wherein a pH of the polishing slurry is 2.2 to 10.2.

12. The method of claim 11 , wherein a diameter at which a cumulative volume is 50% in a particle size distribution of the manganese dioxide particles measured by a dynamic light scattering method is 200 nm or more and 2000 nm or less.

13. The method of claim 12 , wherein said polishing is performed at a polishing speed of at least 7.2 μm/h.

14. The method of claim 1 , wherein said polishing is a primary polishing, wherein the method further comprises a secondary polishing of the substrate, the secondary polishing is performed after said primary polishing.

15. The method of claim 14 , wherein a D50 of particles using in the secondary polishing is smaller than a D50 of the manganese dioxide particles used in the primary polishing with the polishing slurry.

16. A method of manufacturing a gallium oxide substrate, the method comprising:
polishing the gallium oxide substrate with a polishing slurry,
wherein the polishing slurry contains manganese dioxide particles and water and a pH of the polishing slurry is 1 or more and 3 or less, and
wherein said polishing is performed at a polishing speed of at least 7.2 μm/h.

17. The method of claim 16 , wherein an amount of the manganese dioxide particles contained in the polishing slurry is 0.01% by mass or more and 50% by mass or less.

18. The method of claim 16 , wherein a diameter at which a cumulative volume is 50% in a particle size distribution of the manganese dioxide particles measured by a dynamic light scattering method is 1 nm or more and 2000 nm or less.

19. The method of claim 16 , further comprising cleaning the gallium oxide substrate with a cleaning liquid after the polishing of the gallium oxide substrate.

20. The method of claim 19 , wherein the cleaning liquid contains ascorbic acid, erythorbic acid, or a combination of both, and has a pH of 6 or less.

21. The method of claim 19 , wherein the cleaning liquid contains sulfuric acid, hydrochloric acid, or a combination of both, and contains hydrogen peroxide.

22. The method of claim 16 , wherein the gallium oxide substrate is a single crystal gallium oxide substrate.

Assignees

• Agc Inc

Inventors

• Hirabayashi Yusuke

Classifications

• H10P90/129 Primary

  by polishing · CPC title

• C23F3/00

  Brightening metals by chemical means · CPC title

• C09K3/1463

  Aqueous liquid suspensions · CPC title

• C09K3/1409

  Abrasive particles per se (preparation of diamond C01B32/25) · CPC title

• B24B37/00

  Lapping machines or devices; Accessories (B24B3/00 takes precedence) · CPC title