YTTRIA SINTERED COMPACT AND MEMBER FOR PLASMA PROCESSING APPARATUS

PROBLEM TO BE SOLVED: To provide an yttria sintered compact capable of being used for a part exposed to a plasma of a plasma processing apparatus. SOLUTION: The yttria sintered compact has an average crystal diameter of not greater than 3 μm, a porosity of not greater than 1% and a flexural strength of not less than 180 MPa. The yttria sintered compact may preferably have a surface roughness (Ra) of 0.05-5 μm. Further, the yttria sintered compact may more preferably satisfy the relationship of the following formula (1): E≤1.20×E0(1) where E and E0in the formula (1) denote etching rates (nm/min) when performing plasma processing under the same condition to yttria sintered compacts of the same material but different in surface roughness respectively, and E0denotes an etching rate (nm/min) of the yttria sintered compact having a surface roughness (Ra) of 0.05 μm. COPYRIGHT: (C)2009,JPO&INPIT