Investigation on the gate insulator thickness dependence of ZnO–SnO2 thin film transistors

The effect of gate insulator thickness on the properties of ZnO–SnO2 (ZTO) thin film transistors (TFTs) was investigated. The ZTO TFTs with gate insulator thickness ranging from 100 to 400 nm were fabricated in a low temperature process. The drain source current sharply increased with decreasing gate insulator films thickness. Also, the field effect mobility remarkably increased and subthreshold swing decreased with decreasing gate insulator film thickness. It is found that the gate insulator thickness is important for the proper operation of ZTO TFTs in a low temperature process.