Method for manufacturing semiconductor device

摘要

An object is to manufacture a semiconductor device including an oxide semiconductor film, which has stable electric characteristics and high reliability. A crystalline oxide semiconductor film is formed, without performing a plurality of steps, as follows: by utilizing a difference in atomic weight of plural kinds of atoms included in an oxide semiconductor target, zinc with low atomic weight is preferentially deposited on an oxide insulating film to form a seed crystal including zinc; and tin, indium, or the like with high atomic weight is deposited on the seed crystal while causing crystal growth. Further, a crystalline oxide semiconductor film is formed by causing crystal growth using a seed crystal with a hexagonal crystal structure including zinc as a nucleus, whereby a single crystal oxide semiconductor film or a substantially single crystal oxide semiconductor film is formed.

主权项

1. A method for manufacturing a semiconductor device, comprising the steps of:
forming a gate electrode over a substrate; forming a gate insulating film comprising an oxide insulating film over the gate electrode; forming a seed crystal with a hexagonal crystal structure including zinc by a sputtering method over the gate insulating film; causing a crystal growth using the seed crystal as a nucleus while depositing indium over the seed crystal to form a crystalline oxide semiconductor film having a hexagonal crystal structure; performing a heat treatment on the crystalline oxide semiconductor film; etching the crystalline oxide semiconductor film after the heat treatment; and forming a pair of electrodes over the crystalline oxide semiconductor film after the etching step.