Patent ID: 8030177

Claim:
A method for manufacturing a semiconductor device, comprising the steps of: forming a first insulating film over a surface of a first single crystal silicon substrate; forming a second insulating film over a surface of a second single crystal silicon substrate; doping an entire surface of the first single crystal silicon substrate with first ions through the first insulating film to form a first embrittlement layer in the first single crystal silicon substrate; doping the second single crystal silicon substrate with second ions through the second insulating film to selectively form a second embrittlement layer in the second single crystal silicon substrate; bonding the first single crystal silicon substrate and the second single crystal silicon substrate to each other with the first insulating film and the second insulating film interposed therebetween; separating part of the first single crystal silicon substrate along the first embrittlement layer by first heat treatment to form a first single crystal silicon film over the second single crystal silicon substrate with the first insulating film and the second insulating film interposed therebetween; forming a third insulating film over the first single crystal silicon film; removing a region of the second single crystal silicon substrate, in which the second embrittlement layer is not formed; bonding a base substrate and the second single crystal silicon substrate to each other with the third insulating film interposed therebetween; separating part of the second single crystal silicon substrate along the second embrittlement layer by second heat treatment to form a second single crystal silicon film over the base substrate with the first insulating film and the second insulating film interposed therebetween; selectively removing the second single crystal silicon film to form an island-like second single crystal silicon film, and removing part of the first insulating film and part of the second insulating film to expose the first single crystal silicon film; and selectively removing the first single crystal silicon film to form an island-like first single crystal silicon film, wherein in the case where a plane orientation of a main surface of the first single crystal silicon substrate is (100), a plane orientation of a main surface of the second single crystal silicon substrate is (110), wherein in the case where the plane orientation of the main surface of the first single crystal silicon substrate is (110), the plane orientation of the main surface of the second single crystal silicon substrate is (100), wherein a dose of the second ions is smaller than a dose of the first ions, and wherein a temperature of the second heat treatment is higher than a temperature of the first heat treatment.