Thin-film transistor and display device oxide semiconductor and gate dielectric having an oxygen concentration gradient

Abstract

The thin-film transistor of the present invention has at least a semiconductor layer including: on a substrate, a source electrode, a drain electrode, and a channel region; a gate insulating film; and a gate electrode, wherein the semiconductor layer is an oxide semiconductor layer, and wherein the gate insulating film is amorphous silicon including at least O and N, and the gate insulating film has a distribution of an oxygen concentration in a thickness direction so that the oxygen concentration is high in the side of an interface with an oxide semiconductor layer and the oxygen concentration decreases toward the side of the gate electrode.

Description

technical field

[0001] The present invention relates to a thin film transistor including amorphous silicon containing at least O and N as a gate insulating film, and a display device using the transistor. Background technique

[0002] In recent years, as also disclosed in Japanese Patent Application Laid-Open No. 2002-076356, development of thin film transistors (TFTs) each of which will contain a transparent conductive oxide containing ZnO as a main component has been actively carried out. A polycrystalline thin film is used for the channel layer.

[0003] Since the above thin film can be formed into a film at low temperature and is transparent to visible light, a flexible transparent TFT can be formed on a substrate such as a plastic plate or film.

[0004] Furthermore, Japanese Patent Application Laid-Open No. 2003-086808 discloses that in a thin film transistor having a transparent semiconductor using ZnO or the like, an insulating layer is formed in a two-layer structu...

Images