Semiconductor device and method of manufacturing the same

摘要

It is an object to manufacture a semiconductor device in which a transistor including an oxide semiconductor has normally-off characteristics, small fluctuation in electric characteristics, and high reliability. First, first heat treatment is performed on a substrate, a base insulating layer is formed over the substrate, an oxide semiconductor layer is formed over the base insulating layer, and the step of performing the first heat treatment to the step of forming the oxide semiconductor layer are performed without exposure to the air. Next, after the oxide semiconductor layer is formed, second heat treatment is performed. An insulating layer from which oxygen is released by heating is used as the base insulating layer.

主权项

1. A semiconductor device comprising:
a first insulating layer over and in contact with a substrate; an oxide semiconductor layer over and in contact with the first insulating layer; a gate electrode overlapping with the oxide semiconductor layer; and a second insulating layer between the oxide semiconductor layer and the gate electrode, wherein a hydrogen concentration at an interface between the substrate and the first insulating layer is less than or equal to 1.1×1020 atoms/cm3.