Patent ID: 7842583

Claim:
A method for manufacturing a semiconductor substrate, comprising the steps of: forming a buffer layer on each of a plurality of single crystal semiconductor substrates; forming a damaged region in a region at a depth from a surface of single crystal semiconductor substrate, the damaged region being formed by irradiating each of the plurality of single crystal semiconductor substrates with accelerated ions; performing a substrate fixing treatment to fix one or more of the plurality of single crystal semiconductor substrates to a base substrate by bonding a surface of the buffer layer and a surface of the base substrate; performing an electromagnetic wave irradiation treatment to divide the one or more of the plurality of single crystal semiconductor substrates fixed to the base substrate by the substrate fixing treatment along the damaged region by irradiating the one or more of the plurality of single crystal semiconductor substrates with an electromagnetic wave having a frequency of 300 MHz to 300 GHz; and performing the substrate fixing treatment and the electromagnetic wave irradiation treatment twice or more to form a semiconductor substrate where a plurality of single crystal semiconductor layers is fixed to the base substrate.