High mobility a-IGO films produced at room temperature and their application in TFTs

Abstract

The effect of oxygen partial pressure on the properties of In2 O3 - Ga2 O3 thin films produced by sputtering at room temperature aimed at thin film transistor (TFT) application is reported in this work. When produced in the absence of oxygen, the films are polycrystalline, while in the presence of oxygen, the films are amorphous. The films' resistivity is tuned between 10-3 and 104 γ cm. Moreover, the films present a high transmittance (> 80%) and a smooth surface (rrms =1.2 nm). The high performance as-produced transistors present high saturation mobility (μsat ≈43 cm2 /V s) and a subthreshold gate-voltage swing of 0.51 V/dec, which is reduced to 0.27 V/dec after 150°C annealing. © 2009 The Electrochemical Society.