Patent ID: 7820524

Claim:
A manufacturing method of an SOI substrate, the manufacturing method comprising: forming a protective film over a semiconductor substrate, forming an ion introduction layer in the semiconductor substrate by applying an ion beam to the semiconductor substrate; forming a first bonding layer over the protective film; forming a first insulating layer over a base substrate; forming a second insulating layer over the first insulating layer; forming a second bonding layer over the second insulating layer; bonding the semiconductor substrate to the base substrate with the first bonding layer and the second bonding layer interposed therebetween; heating the semiconductor substrate and the base substrate to separate a part of the semiconductor substrate at the ion introduction layer, leaving a semiconductor layer over the base substrate; irradiating the semiconductor layer with laser light; and thinning the semiconductor layer by etching the semiconductor layer, wherein the ion beam is formed by exciting a source gas containing one or a plurality of gases selected from a hydrogen gas, a rare gas, a halogen gas, or a halogen-containing gas.