Gallium nitride sintered body or gallium nitride molded article, and method for producing same

Patent metadata

Field	Value
Publication number	US-11168393-B2
Application number	US-201816206346-A
Country	US
Kind code	B2
Filing date	Nov 30, 2018
Priority date	Dec 20, 2010
Publication date	Nov 9, 2021
Grant date	Nov 9, 2021

Abstract

The present invention provides a gallium nitride sintered body and a gallium nitride molded article which have high density and low oxygen content without using a special apparatus. According to the first embodiment, a gallium nitride sintered body, which is characterized by having density of 2.5 g/cm3 to less than 5.0 g/cm3 and an intensity ratio of the gallium oxide peak of the (002) plane to the gallium nitride peak of the (002) plane of less than 3%, which is determined by X-ray diffraction analysis, can be obtained. According to the second embodiment, a metal gallium-impregnated gallium nitride molded article, which is characterized by comprising a gallium nitride phase and a metal gallium phase that exist as separate phases and having a molar ratio, Ga/(Ga+N), of 55% to 80%, can be obtained.

First claim

The invention claimed is:

1. A metal gallium-impregnated gallium nitride molded article, wherein
the molded article comprises
a gallium nitride phase having voids contained therein and
a metal gallium phase
which exist as separate phases, and
the molded article has a molar ratio of Ga/(Ga+N) of 55% to 80%,
wherein said gallium nitride phase has a density of 2.5 g/cm 3 to less than 5.0 g/cm 3 and a composition having an intensity ratio of a gallium oxide peak of the (002) plane to a gallium nitride peak of the (002) plane of less than 3%, as determined by X-ray diffraction analysis.

2. The metal gallium-impregnated gallium nitride molded article according to claim 1 , wherein not less than 30% of a total volume of said voids contained therein is filled with said metal gallium.

3. The metal gallium-impregnated gallium nitride molded article according to claim 1 , wherein the molded article has density of 3.20 g/cm 3 to less than 6.05 g/cm 3 .

4. The metal gallium-impregnated gallium nitride molded article according to claim 1 , wherein the molded article has resistance of not higher than 1 Ω·cm.

5. The metal gallium-impregnated gallium nitride molded article according to claim 1 , wherein the molded article contains oxygen in an amount of not more than 11 atm %.

6. The metal gallium-impregnated gallium nitride molded article according to claim 1 , wherein
said voids contained therein comprise open pores and closed pores, and
the volume ratio of said open pores with respect to a total volume of said voids is not less than 70%.

7. A method of producing the metal gallium-impregnated gallium nitride molded article according to claim 1 , wherein the method comprises impregnating a liquid metal gallium into a gallium nitride molded article having density of 2.0 g/cm 3 to less than 5.0 g/cm 3 .

8. The method according to claim 7 , wherein said impregnating the liquid metal gallium into a gallium nitride molded article includes
subjecting said gallium nitride molded article and said metal gallium to a vacuum treatment in the same container and then
isotropically applying a pressure to said container.

9. The method according to claim 7 , wherein said gallium nitride molded article is obtained by a process comprising:
obtaining a molded article by sintering a gallium nitride powder having
a specific surface area (BET) of 0.4 m 2 /g to 15 m 2 /g,
untamped bulk density of not less than 0.4 g/cm 3 , and
a repose angle of not larger than 40°; and
heat-treating the obtained molded article in an ammonia-containing atmosphere.

10. The method according to claim 9 , wherein said gallium nitride powder is obtained by subjecting a gallium oxide powder to a nitridation treatment in an ammonia atmosphere at a temperature of 1000° C. to 1100° C.

11. A gallium nitride sputtering target, comprising the metal gallium-impregnated gallium nitride molded article according to claim 1 .

Assignees

• Tosoh Corp

Inventors

• Mesuda Masami
• Matsumaru Keitaro
• Takahashi Koyata
• Kikuchi Ryou
• Shibutami Tetsuo

Classifications

• C04B38/0093

  Other features · CPC title

• C04B37/026

  consisting of metals or metal salts · CPC title

• C04B2235/662

  Annealing after sintering · CPC title

• C23C14/3414 Primary

  Metallurgical or chemical aspects of target preparation, e.g. casting, powder metallurgy · CPC title

• C04B35/6261

  Milling · CPC title