Influence of Interface Traps on the Electrical Properties of Oxide Thin-Film Transistors with Different Channel Thicknesses

Abstract

The electrical properties of bottom-gate amorphous InSnZnO (a-ITZO) thin-film transistors (TFTs) with different channel thicknesses (TITZO) were investigated. The difference between front- and back-channel interface traps influence on subthreshold swing (S) and turn on voltage (Von) of a-ITZO TFTs was further analyzed using device simulation. Variations of front-channel interface traps (Naf) on S and Von were hardly dependent on TITZO. However, variations of S and Von became larger for thinner TITZO TFT when back-channel interface traps (Nabk) varied; which can be explained by considering screening length. Not only Naf but also Nabk are important factors of S and Von to achieve high performance thinner oxide TFT.