A member used within a plasma processing apparatus and exposed to a plasma of
a
halogen gas such as BCl3 or Cl2 is formed from a sintered
body of metals of Group IIIa of Periodic Table such as Y, La, Ce, Nd and Dy, and
Al and/or Si, for example, 3Y2O3.5Al2O3,
2Y2O3.Al2O3, Y2O3.Al2O3
or disilicate or monosilicate, and in particular, in this sintered body,
the content of impurity metals of Group IIa of Periodic Table contained in the
sintered body is controlled to be 0.15 wt % or more in total. Specifically, for
this member, an yttrium-aluminum-garnet sintered body having a porosity of 3% or
less and also having a surface roughness of 1 m or less in center line average
roughness Ra is utilized.
