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 (V (th) ) and field effect mobility (A mu (FE) ) 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 (V (th) ) 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.