SEMICONDUCTOR DEVICE AND MANUFACTURING METHOD THEREOF

摘要

An object of an embodiment of the present invention is to provide a semiconductor device which includes a transistor including an oxide semiconductor with high field-effect mobility, a small variation in threshold voltage, and high reliability. The semiconductor device includes a transistor which includes an insulating substrate from which oxygen is released by heat treatment and an oxide semiconductor film over the insulating substrate. A channel is formed in the oxide semiconductor film. The insulating substrate from which oxygen is released by heat treatment can be manufactured by implanting oxygen ions into at least a region of an insulating substrate on the side provided with the oxide semiconductor film.