Low Temperature Processed InGaZnO Oxide Thin Film Transistor Using Ultra-Violet Irradiation

Abstract

Device performance and bias stability of InGaZnO (IGZO) thin film transistors (TFTs) were investigated as a function of post-treatment with the combination of ultra-violet (UV) irradiation and thermal annealing. Under low temperature annealing at 150 degrees C after UV irradiation, the device performance and bias stability of IGZO TFTs were enhanced with field effect mobility of 10.14 cm(2)/Vs and Delta V-th below 0.5 V. The electrical characteristics of IGZO TFTs improved without a change in the physical structure and the origin of enhanced device performance can be explained by the changes of the oxygen coordination and the evolution of the electronic structures, such as the band edge states and band alignment of the Fermi level within the bandgap.