Patent ID: 8349702

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; forming an insulating layer over the single crystal semiconductor substrate; bonding the insulating layer and a supporting substrate to each other; separating the single crystal semiconductor substrate at the damaged region to form a first single crystal semiconductor layer over the supporting substrate; forming a first semiconductor layer over the first single crystal semiconductor layer; forming a second semiconductor layer over the first semiconductor layer with a different condition from that used for forming the first semiconductor layer so that hydrogen concentration of the second semiconductor layer is higher than that of the first semiconductor layer; and improving crystallinity of the first semiconductor layer and the second semiconductor layer by a solid-phase growth to form a second single crystal semiconductor layer, wherein the first semiconductor layer and the second semiconductor layer are formed so that the crystallinity of the first semiconductor layer is higher than that of the second semiconductor layer.