Patent Number: 6,166,432

Title: Substrate for use in wafer attracting apparatus and manufacturing method thereof

Abstract: 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.sup.2.

Inventors: Ohno; Masashi (Nagoya, JP), Yamada; Naohito (Kasugai, JP), Inoue; Takahiro (Gifu, JP), Kato; Kouji (Nagoya, JP)

Assignee: NGK Insulators, Ltd.

International Classification: H01L 21/683 (20060101); H01L 21/67 (20060101); H01L 023/053 (); H01L 023/12 ()

Expiration Date: 12/26/2017