METHOD FOR MANUFACTURING SOI SUBSTRATE

摘要

An insulating layer is formed on a surface of a semiconductor wafer which is to be a bond substrate and an embrittlement region is formed in the semiconductor wafer by irradiation with accelerated ions. Then, a base substrate and the semiconductor wafer are attached to each other. After that, the semiconductor wafer is divided at the embrittlement region by performing heat treatment and an SOI substrate including a semiconductor layer over the base substrate with the insulating layer interposed therebetween is formed. Before the SOI substrate is formed, heat treatment is performed on the semiconductor wafer at a temperature of higher than or equal to 1100° C. under a non-oxidizing atmosphere in which the concentration of impurities is reduced. In this manner, the planarity of the film formed on the semiconductor wafer when heat treatment is performed can be improved.