Importance

Loading Importance Indicators...

Abstract

In a thin film transistor, a gate insulating film having a first insulating film and a second insulating film is formed on a gate electrode, and a semiconductor layer including ZnO etc. is formed on the second insulating film. The first insulating film is formed by using SiN.sub.x having a high insulating characteristic, and the second insulating film is formed by using an oxide (for example, SiO.sub.2). This structure improves a crystalline characteristic of the semiconductor layer that constitutes an interface in combination with the second insulating film, and decreases a defective level of the interface between the semiconductor layer and the second insulating film. Further, the second insulating film is constituted of the oxide, so that it is possible to restrain a material for the second insulating film from depriving oxygen of the semiconductor layer. This keeps a crystalline characteristic of the semiconductor layer under a preferable condition in the vicinity of the interface between the second insulating film and the semiconductor layer. As a result, it is possible to realize a thin film transistor such that: a leak current level at an OFF area is low, and the mobility is high, and a switching characteristic is preferable. Thus, in the thin film transistor having a transparent semiconductor film, a TFT characteristic is improved.

Loading the Abstract Image...

First Claim