Patent ID: 7176102

Claim:
An SOI wafer produced by a hydrogen ion delamination method, the method comprising at least a step of bonding a base wafer and a bond wafer having a micro bubble layer formed by gas ion implantation and a step of delaminating a wafer having an SOI layer at the micro bubble layer as a border, wherein, after the delamination step, the wafer having an SOI layer is subjected, in an atmosphere containing hydrogen or argon, to both a heat treatment utilizing a rapid heating/rapid cooling apparatus to improve the surface roughness of short periods of the SOI layer and a heat treatment utilizing a batch processing type furnace to improve the surface roughness of long periods of the SOI layer; and wherein the wafer has an RMS value of 0.5 nm or less concerning surface roughness for both of 1 μm square and 10 μm square.