Patent ID: 8138063

Claim:
A method for manufacturing a semiconductor device comprising the steps of: forming a first semiconductor film over a substrate having an insulating surface; implanting a first conductivity type impurity into the first semiconductor film; forming an ion separation layer in a region of a predetermined depth below a surface of a single crystal semiconductor substrate by irradiating the single crystal semiconductor substrate with at least one kind of ions generated by plasma excitation of a source gas selected from the group consisting of hydrogen, helium, and halogen, wherein the ions are constituted by the same element; after implanting the first conductivity type impurity, bonding the surface of the single crystal semiconductor substrate to the surface of the first semiconductor film; generating a crack in the ion separation layer by heating the bonded single crystal semiconductor substrate and the first semiconductor film; and forming a second semiconductor film by separating the single crystal semiconductor substrate at the crack in the ion separation layer with the second semiconductor film left on the first semiconductor film.