PLASMA CORROSION RESISTANT MEMBER

摘要

PROBLEM TO BE SOLVED: To obtain a member more excellent in corrosion resistance to plasma and having a long service life by forming a member from an aluminum nitride sintered compact having a specified average grain diameter and specifying the average surface roughness of the surface of the member brought into contact with plasma. SOLUTION: A member is formed from an aluminum nitride sintered compact having 1-20 μm average grain diameter and the average surface roughness of the surface of the member brought into contact with plasma is reduced to <=0.5 μm. The aluminum nitride sintered compact is obtd. as usual. In order to very smoothly finish the surface brought into contact with plasma, grinding and/or polishing is adopted. Since aluminum nitride has much higher heat conductivity and a lower coefft. of thermal expansion than alumina, large thermal stress is less liable to occur in aluminum nitride and excellent corrosion resistance to plasma and a long service life are ensured.