CaF2 POLYCRYSTALLINE BODY, FOCUS RING, PLASMA PROCESSING APPARATUS, AND METHOD FOR PRODUCING CaF2 POLYCRYSTALLINE BODY

摘要

A CaF₂ polycrystalline body which is a polycrystalline body constituted of CaF₂ and of which an average grain size of crystalline grains is 200 μm or more, and a method for producing a CaF₂ polycrystalline body, the method including a process of introducing a compact which is obtained by using a CaF₂ powder raw material into a vacuum sintering furnace and sintering at a temperature of not higher than 1400° C. for six hours or more, thereby obtaining the CaF₂ polycrystalline body.