Patent ID: 8067820

Claim:
A method of supporting a silicon wafer having crystal orientation <100> or a silicon wafer having crystal orientation <110> for heat treatment thereof using a wafer boat, wherein: (i) in the case of the <110> wafer, a back side of the silicon wafer is supported by the wafer boat (a) in a datum region comprising a fan-shaped region of a surface of the silicon wafer in a range of 40° to 60° relative to a reference direction in parallel to the silicon wafer surface, the reference direction being from the center of the silicon wafer toward <100> and (b) in at least one other region which is distanced from the datum region by one or more 90° increments; and (ii) in the case of the <100> wafer, a back side of the silicon wafer is supported by the wafer boat (a) in a datum region comprising a fan-shaped region of the silicon wafer surface in the range of 40° to 60° relative to a reference direction, the reference direction being toward <110> and (b) in at least one other region regions which is distanced from the datum region by one or more 90° increments.