Method for manufacturing SOI substrate

摘要

An object of an embodiment of the present invention to be disclosed is to prevent oxygen from being taken in a single crystal semiconductor layer in laser irradiation even when crystallinity of the single crystal semiconductor layer is repaired by irradiation with a laser beam; and to make substantially equal or reduce an oxygen concentration in the semiconductor layer after the laser irradiation comparing before the laser irradiation. A single crystal semiconductor layer which is provided over a base substrate by bonding is irradiated with a laser beam, whereby the crystallinity of the single crystal semiconductor layer is repaired. The laser irradiation is performed under a reducing atmosphere or an inert atmosphere.

主权项

1. A method for manufacturing an SOI substrate comprising the steps of:
irradiating a single crystal semiconductor substrate with ions to form an embrittlement region in the single crystal semiconductor substrate; bonding the single crystal semiconductor substrate and a base substrate with an insulating layer interposed therebetween; separating the single crystal semiconductor substrate at the embrittlement region to form a single crystal semiconductor layer over the base substrate with the insulating layer interposed therebetween; and irradiating the single crystal semiconductor layer with a laser beam under a reducing atmosphere including at least hydrogen gas to melt at least a surface portion of the single crystal semiconductor layer to recrystallize the single crystal semiconductor layer, wherein an oxygen concentration in the single crystal semiconductor layer after the irradiation with the laser beam is less than 1×1018 atoms/cm3.