Semiconductor device and manufacturing method thereof

摘要

One embodiment of the present invention is to achieve high mobility in a device using an oxide semiconductor and provide a highly reliable display device. An oxide semiconductor layer including a crystal region in which c-axis is aligned in a direction substantially perpendicular to a surface is formed and an oxide insulating layer is formed over and in contact with the oxide semiconductor layer. Oxygen is supplied to the oxide semiconductor layer by third heat treatment. A nitride insulating layer containing hydrogen is formed over the oxide insulating layer and fourth heat treatment is performed, so that hydrogen is supplied at least to an interface between the oxide semiconductor layer and the oxide insulating layer.

主权项

1. A semiconductor device comprising:
a first gate electrode; an oxide semiconductor layer over the first gate electrode, the oxide semiconductor layer including a crystal region in which c-axis is aligned in a direction, wherein an angle between the direction and a surface of the oxide semiconductor layer is within a range of 80° to 100°; a second gate electrode over the oxide semiconductor layer; a nitride insulating layer containing hydrogen over the oxide semiconductor layer.