Investigation of the Low-Frequency Noise Behavior and Its Correlation with the Subgap Density of States and Bias-Induced Instabilities in Amorphous InGaZnO Thin-Film Transistors with Various Oxygen Flow Rates

Abstract

The low-frequency noise (LFN) behavior and its correlation with the subgap density of states (DOSs) and bias-induced instabilities are investigated in the amorphous indium-gallium-zinc-oxide (a-IGZO) thin-film transistors (TFTs) with various oxygen flow rates. Higher LFN is measured in the higher oxygen flow rate devices in the subthreshold regime, which is attributed to the increased trapping/release processes. We also obtain higher subgap DOSs and larger threshold voltage shifts under positive bias stresses in higher oxygen flow rate devices, which represents that the LFN measured in the subthreshold regime is deeply correlated with the subgap DOSs and electrical instabilities in a-IGZO TFTs. (C) 2012 The Japan Society of Applied Physics