Substrate for use in wafer attracting apparatus and manufacturing method thereof

摘要

A wafer attracting apparatus includes a substrate made of a ceramic material and adapted to attract and hold a wafer onto an attracting surface thereof, wherein the attracting surface is constituted by a ductile worked surface, the ductile worked surface has concave portions, a diameter of each of the concave portions is 0.1 mu m or less, and when the wafer is attracted onto the attracting surface of the substrate and released therefrom, the number of particles attaching to that wafer is 9.3 or less per 1 cm<2>.