Investigation of co-sputtered LiZnSnO thin film transistors

Abstract

We proposed the fabrication of Li–Zn–Sn–O (LZTO) thin film transistors (TFTs) using a magnetron co-sputtering method. To analyze the effects of Li incorporation on the amorphous LZTO TFTs, Hall measurement and X-ray photoelectron spectroscopy were performed. It was found that the increased addition of Li to the ZTO system caused the suppression of carrier creation. At an optimized condition (~12at.% Li) for LZTO TFTs, we achieved a saturation mobility of ~10.4cm2/Vs, a subthreshold voltage of 0.25V/decade, a threshold voltage (Vth) of 3.9V, and an Ion/off ratio of 2×108. Furthermore, the optimized device exhibited much better photo-bias stability (ΔVth=−3.3V) than the reference ZTO device (ΔVth=−10.8V) under the negative bias illumination stress condition.