Method for manufacturing a semiconductor device

摘要

It is an object to provide a highly reliable semiconductor device with good electrical characteristics and a display device including the semiconductor device as a switching element. In a transistor including an oxide semiconductor layer, a needle crystal group provided on at least one surface side of the oxide semiconductor layer grows in a c-axis direction perpendicular to the surface and includes an a-b plane parallel to the surface, and a portion except for the needle crystal group is an amorphous region or a region in which amorphousness and microcrystals are mixed. Accordingly, a highly reliable semiconductor device with good electrical characteristics can be formed.

主权项

1. A method for manufacturing a semiconductor device comprising the steps of:
performing a first heat treatment in a chamber in which a substrate and a target are provided; forming an oxide semiconductor film over the substrate by sputtering method using the target; and performing a second heat treatment on the oxide semiconductor film, wherein the oxide semiconductor film is formed in the chamber without exposure to air after the first heat treatment, wherein moisture remaining on an inner wall of the chamber and moisture remaining in the target are reduced by the first heat treatment, wherein gas in the chamber is exhausted during the first heat treatment, and wherein hydrogen or moisture in the oxide semiconductor film is reduced by the second heat treatment.