Variation of subthreshold swing of solution-processed Zr-Si-In-Zn-O thin film transistor at low annealing temperature

Abstract

The effect of zirconium contents (from 0.01 to 1.6 molar ratios) on the change of threshold voltage (Vth) and field effect mobility (µFE) of solution processed zirconium silicon-gallium-zinc oxide (Zr-SIZO) thin film transistors (TFTs) has been reported. We have studied the effect of Zr contents on the threshold voltage (Vth) and subthreshold swing (S.S) of Zr-SIZO TFTs. As the content of Zr ions increased in Zr-SIZO, the threshold voltage shifted from −4.8 to 4.4 V. Also, off-current in the TFTs decreased mainly because Zr is more easily oxidized than Si, In, or Zn since it has a low standard electrical potential (SEP). Thus, Zr could be expected to be a carrier suppressor in the Zr-SIZO system. This suggests that the performance of SIZO TFTs can be controlled by the Zr molar ratio in the Zr-SIZO based TFTs.