Semiconductor device having oxide semiconductor layer

摘要

Disclosed is a highly reliable semiconductor device and a manufacturing method thereof, which is achieved by using a transistor with favorable electrical characteristics and high reliability as a switching element. The semiconductor device includes a driver circuit portion and a pixel portion over one substrate, and the pixel portion comprises a light-transmitting bottom-gate transistor. The light-transmitting bottom-gate transistor comprises: a transparent gate electrode layer; an oxide semiconductor layer over the gate electrode layer, a superficial layer of the oxide semiconductor layer including comprising a microcrystal group of nanocrystals; and source and drain electrode layers formed over the oxide semiconductor layer, the source and drain electrode layers comprising a light-transmitting oxide conductive layer.