The electrical performance and gate bias stability of an amorphous InGaZnO thin-film transistor with HfO2 high-k dielectrics

In this study, we set out to fabricate an amorphous indium gallium zinc oxide (a-IGZO) thin-film transistor (TFT) with SiNx/HfO2/SiNx (SHS) sandwiched dielectrics. The J-V and C-V of this SHS film were extracted by the Au/p-Si/SHS/Ti structure. At room temperature the a-IGZO with SHS dielectrics showed the following electrical properties: a threshold voltage of 2.9 V, a subthreshold slope of 0.35 V/decade, an on/off current ratio of 3.5 × 107, and a mobility of 12.8 cm2 V−1 s−1. Finally, we tested the influence of gate bias stress on the TFT, and the result showed that the threshold voltage shifted to a positive voltage when applying a positive gate voltage to the TFT.