Numerical study on the scaling of a-Si:H thin film transistors

Abstract

In this article we discuss the impact of channel length scaling on the above threshold current characteristics of hydrogenated amorphous silicon (a-Si:H) thin film transistors (TFTs). MEDICI simulation results of the interface surface potential show a lowering of the potential barrier for shorter channel lengths. This suggests a decrease in threshold voltage and increase in subthreshold slope with drain voltage particularly in submicron channel lengths, causing a nonsaturating output current. Simulation results of the above threshold current-voltage characteristics for short channel TFTs corroborate with measurement data of fabricated devices.