Patent ID: 8481393

Claim:
A method for manufacturing a semiconductor substrate comprising: irradiating a single crystal semiconductor substrate with ions, to form a damaged region in the single crystal semiconductor substrate at a predetermined depth from a surface of the single crystal semiconductor substrate; forming a buffer layer over at least one of a supporting substrate and the single crystal semiconductor substrate; etching a part of the buffer layer, a part of the damaged region, and a part of the single crystal semiconductor substrate, so that the single crystal semiconductor substrate is divided into a plurality of single crystal semiconductor substrates; disposing the supporting substrate and the plurality of single crystal semiconductor substrates with the buffer layer interposed therebetween to fix the plurality of single crystal semiconductor substrates to the supporting substrate; separating the plurality of single crystal semiconductor substrates from the supporting substrate at the damaged region to form a plurality of single crystal semiconductor layers separated from the single crystal semiconductor substrates; irradiating the plurality of single crystal semiconductor layers with a laser beam to partly melt each of the single crystal semiconductor layers, so that the single crystal semiconductor layers are recrystallized; and heating the plurality of recrystallized single crystal semiconductor layers at a temperature which is higher than or equal to 400° C. and at which the plurality of recrystallized single crystal semiconductor layers are not melted.