Patent ID: 7204887
Filing Date: 2007-04-17
Classification: H01L,Y10S

Abstract:
1. A wafer holder to hold a wafer on the upper surface characterized in that: the wafer holder comprises a wafer support plate and three or more wafer support members mounted on said wafer support plate, wherein said wafer support members maintain rigidity and each having one or more wafer support portions; wherein said wafer support members are fabricated from a material selected from the group consisting of SiC, Si 3 N 4 , Si and combinations thereof; at least one of said wafer support members is a tilting wafer support member which has a plurality of upward-convex wafer support portions on the upper surface; and is tiltable by a fulcrum located between said tilting wafer support member and the wafer support plate with respect to the wafer support plate; and the wafer is supported by at least four wafer support portions by point contact; including point contact by the upward-convex wafer support portions located on said upper surface of said tilting wafer support member.