Abstract: A high-performance semiconductor device using an SOI substrate in which a low-heat-resistance substrate is used as a base substrate. Further, a high-performance semiconductor device formed without using chemical polishing. Further, an electronic device using the semiconductor device. An insulating layer over an insulating substrate, a bonding layer over the insulating layer, and a single-crystal semiconductor layer over the bonding layer are included, and the arithmetic-mean roughness of roughness in an upper surface of the single-crystal semiconductor layer is greater than or equal to 1 nm and less than or equal to 7 nm. Alternatively, the root-mean-square roughness of the roughness may be greater than or equal to 1 nm and less than or equal to 10 nm. Alternatively, a maximum difference in height of the roughness may be greater than or equal to 5 nm and less than or equal to 250 nm.

Abstract: An object is to provide a laser irradiation apparatus and a laser irradiation method with which positions of crystal grain boundaries generated at the time of laser crystallization can be controlled. Laser light emitted from a laser 101 is modulated into laser light having intensity distribution along a long-axis direction through a phase shift mask 103 and is transferred to an amorphous semiconductor film provided over an insulating substrate by a cylindrical lens 104 and a lens 105. The amorphous semiconductor film is crystallized by being scanned with the laser light.

Abstract: It is an object to provide a method of manufacturing a crystalline silicon device and a semiconductor device in which formation of cracks in a substrate, a base protective film, and a crystalline silicon film can be suppressed. First, a layer including a semiconductor film is formed over a substrate, and is heated. A thermal expansion coefficient of the substrate is 6×10?7/° C. to 38×10?7/° C., preferably 6×10?7/° C. to 31.8×10?7/° C. Next, the layer including the semiconductor film is irradiated with a laser beam to crystallize the semiconductor film so as to form a crystalline semiconductor film. Total stress of the layer including the semiconductor film is ?500 N/m to +50 N/m, preferably ?150 N/m to 0 N/m after the heating step.