Wafer holding, wafer support member, wafer boat and heat treatment furnace

A wafer holder to hold a wafer on the upper surface characterized by comprising:

• a wafer support plate;
• three or more wafer support members placed on said wafer support plate, at least one of which is a first tilting wafer support member having a flat upper surface and a fulcrum provided substantially at the center of the bottom surface and contacting the wafer support plate at a point or along a line and being tiltable with respect to the wafer support plate;
• and at least one second tilting wafer support member located above the flat upper surface of said first tilting wafer support member, said second tilting wafer support member having an upper surface and bottom surface, a fulcrum provided substantially at the center of the bottom surface of said second tilting wafer support member and contacting with said first tilting wafer support member on its flat upper surface at a point or along a line, and a plurality of upward-convex wafer support portions provided on the upper surface of said second tilting wafer support member, wherein each of said wafer support members maintains rigidity, wherein said wafer support members are fabricated from a material selected from the group consisting of SiC, Si3N4, Si and combinations thereof;
• 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 second tilting wafer support member.