Patent ID: 8470648

Claim:
A method for manufacturing a semiconductor device, comprising the steps of: forming a first fragile layer in a first single-crystalline semiconductor substrate by ion irradiation; bonding the first single-crystalline semiconductor substrate over an insulating substrate; separating the first single-crystalline semiconductor substrate at the first fragile layer so that a first single-crystalline semiconductor layer is formed over the insulating substrate; forming a first field-effect transistor using the first single-crystalline semiconductor layer; forming a planarization layer over the first field-effect transistor; forming a second fragile layer in a second single-crystalline semiconductor substrate by ion irradiation; bonding the second single-crystalline semiconductor substrate over the planarization layer; separating the second single-crystalline semiconductor substrate at the second fragile layer so that a second single-crystalline semiconductor layer is formed over the planarization layer; and forming a second field-effect transistor using the second single-crystalline semiconductor layer, wherein the first single-crystalline semiconductor layer and the second single-crystalline semiconductor layer are not overlapped with each other.