Low-Frequency Noise in Amorphous Indium Zinc Oxide Thin Film Transistors with Aluminum Oxide Gate Insulator

Low-frequency noise (LFN) in all operation regions of amorphous indium zinc oxide (a-IZO) thin film transistors (TFTs) with an aluminum oxide gate insulator is investigated. Based on the LFN measured results, we extract the distribution of localized states in the band gap and the spatial distribution of border traps in the gate dielectric, and study the dependence of measured noise on the characteristic temperature of localized states for a-IZO TFTs with Al_2O_3 gate dielectric. Further study on the LFN measured results shows that the gate voltage dependent noise data closely obey the mobility fluctuation model, and the average Hooge's parameter is about 1.18\times10^-3. Considering the relationship between the free carrier number and the field effect mobility, we simulate the LFN using the \Delta N–\Delta\mu model, and the total trap density near the IZO/oxide interface is about 1.23\times 10^18 cm^-3eV^-1.