Semiconductor device including IGZO layer and manufacturing method thereof

摘要

It is an object to provide a thin film transistor having favorable electric characteristics and high reliability and a semiconductor device which includes the thin film transistor as a switching element. An In—Ga—Zn—O-based film having an incubation state that shows an electron diffraction pattern, which is different from a conventionally known amorphous state where a halo shape pattern appears and from a conventionally known crystal state where a spot appears clearly, is formed. The In—Ga—Zn—O-based film having an incubation state is used for a channel formation region of a channel etched thin film transistor.

主权项

1. A method for manufacturing a semiconductor device comprising the steps of:
introducing a substrate into a chamber, wherein the chamber is provided with a target comprising In, Ga and Zn, and wherein a relative density of the target is greater than or equal to 80%; forming an oxide semiconductor layer by sputtering over the substrate, wherein the substrate is heated during the sputtering; removing moisture by using a cryopump from the chamber during forming the oxide semiconductor layer by sputtering; and performing dehydration or dehydrogenation by heat treatment after the oxide semiconductor layer is formed, wherein the oxide semiconductor layer comprises In, Ga and Zn, and wherein a purity of an inert gas which is introduced into a heat treatment apparatus during the heat treatment is set greater than or equal to 99.9999%.