GALLIUM NITRIDE-BASED SINTERED COMPACT AND METHOD FOR MANUFACTURING SAME
The object of the present invention is to provide a sputtering target for a gallium nitride thin film, which has a low oxygen content, a high density and a low resistivity. A gallium nitride powder having powder physical properties of a low oxygen content and a high bulk density is used and hot pressing is conducted at high temperature in high vacuum to prepare a gallium nitride sintered body having a low oxygen content, a high density and a low resistivity.
1 . A gallium nitride-based sintered body, which has an oxygen content of at most 1 atm % and a resistivity of at most 1×10 2 Ω·cm.
2 . The gallium nitride-based sintered body according to claim 1 , which has a density of at least 3.0 g/cm 3 and at most 5.4 g/cm 3 .
3 . The gallium nitride-based sintered body according to claim 1 , which has an average particle size of at least 0.5 μm and at most 3 μm.
4 . The gallium nitride-based sintered body according to claim 1 , which has a weight of at least 10 g.
5 . The gallium nitride-based sintered body according to claim 1 , wherein when it is heat-treated in an air at 250° C. for one hour, there is no visually confirmed deposition of metal gallium from a target member.
6 . A method for producing a gallium nitride-based sintered body by hot pressing, the method comprising:
heating a gallium nitride powder having an oxygen content of at most 2 atm %, as a raw material at a temperature of at least 1,060° C. and less than 1,300° C. with an ultimate vacuum in a chamber of at most 70 Pa at the time of hot pressing.
7 . A gallium nitride sputtering target, comprising:
the gallium nitride sintered-based body as defined in claim 1 .
8 . The gallium nitride sputtering target according to claim 7 , wherein no layer comprising tungsten is present between a target member and a bonding layer.
9 . The gallium nitride sputtering target according to claim 7 , wherein a bonding layer comprises at least one component selected from the group consisting of indium, tin and zinc.
10 . A method for producing a gallium nitride-based thin film, the method comprising:
producing the gallium nitride-based thin film with the gallium nitride sputtering target as defined in claim 7 .