Aluminum nitride sintered body

Abstract

[Object] It is an object of the present invention to provide an aluminum nitride sintered body having resistance to plasma gas and high thermal conduction and having excellent optical properties. [Solution means] The aluminum nitride sintered body of the present invention is characterized in that the proportion of positrons which are annihilated within a period of 180 ps (picoseconds) in the aluminum nitride crystal, as determined in the defect analysis using a positron annihilation method, is not less than 90%, and the sintered body preferably has a thermal conductivity of not less than 200 W/mK.

1 . An aluminum nitride sintered body obtained from raw materials containing an aluminum nitride powder and a sintering additive of an alkaline earth group based oxide, wherein the proportion of positrons which are annihilated within a period of 180 ps (picoseconds) in the aluminum nitride crystal, as determined in the defect analysis using a positron annihilation method, is not less than 90%. 
     
     
         2 . The aluminum nitride sintered body as claimed in  claim 1 , which has a thermal conductivity of not less than 200 W/mK.