Method for fabricating soi substrate

Abstract

There is provided a method for manufacturing an SOI substrate capable of effectively and efficiently embrittling an interface of an ion-implanted layer without causing the separation of a bonded surfaceor the breakage of a bonded wafer. Provided is a method for manufacturing an SOI substrateby forming an SOI layeron a surface of a transparent insulating substrate, the method comprising, in the following order, implanting ions into a silicon waferor a silicon waferwith an oxide filmfrom a surface thereof so as to form an ion-implanted layer; subjecting at least one of the surface of the transparent insulating substrate and the surface of the ion-implanted silicon wafer or the silicon wafer with an oxide film to a surface activation treatment; bonding together the silicon waferor the silicon waferwith an oxide filmand the transparent insulating substrate; subjecting the bonded wafer to a heat treatment at 150° C. or higher but not higher than 350° C. so as to obtain a laminate; and irradiating visible light at a side of the transparent insulating substrateof the laminatetoward the ion-implanted layerof the silicon waferor the silicon waferwith an oxide filmto embrittle an interface of the ion-implanted layerand transfer a silicon thin film to the transparent insulating substrateso that the SOI layercan be formed.