| abstract |
To provide a highly reliable semiconductor device in which a semiconductor device is provided with stable electrical characteristics by using an oxide semiconductor film with stable electrical characteristics. It is another object to provide a semiconductor device with improved mobility by using an oxide semiconductor film with high crystallinity. An oxide semiconductor film with stable electrical characteristics can be formed by forming an oxide semiconductor film having crystallinity in contact with an insulating film with reduced surface roughness. Thus, stable electrical characteristics can be given to the semiconductor device, and a highly reliable semiconductor device can be provided. Furthermore, a semiconductor device with improved mobility can be provided. [Selection] Figure 1 |