Patent ID: 8383491

Claim:
A method for manufacturing an SOI substrate, comprising: forming an insulating film over a semiconductor substrate; irradiating the semiconductor substrate with accelerated ions through the insulating film to form an embrittled region in the semiconductor substrate; disposing a surface of the semiconductor substrate and a surface of a base substrate opposite to each other and bonding the surface of the insulating film to the surface of the base substrate; causing separation along the embrittled region with a heat treatment after the surface of the insulating film and the surface of the base substrate are bonded to each other to form a semiconductor layer over the base substrate with the insulating film interposed therebetween; performing etching treatment on the semiconductor layer; irradiating the semiconductor layer subjected to the etching treatment with a laser beam; and irradiating the semiconductor layer irradiated with the laser beam with plasma using an inert gas.