High- k gate insulating layer IGZTO thin-film transistor with enhanced performance

Abstract Currently, using materials such as Al 2 O 3 and HfO 2 with high dielectric constant, good thermal stability, wide bandgap, and excellent compatibility with silicon substrates to replace SiO 2 as the gate insulating layer of thin-film transistors (TFTs) is an effective way to enhance device performance. These high- k materials endow TFTs with high mobility, low threshold voltage, and low sub-threshold swing characteristics, while ensuring processing capability at room temperature. In this study, high-performance indium gallium zinc tin oxide (IGZTO) TFTs based on Al 2 O 3 and HfO 2 gate insulating layer were prepared. The results show that the high- k gate dielectric TFTs achieve low operating voltage driving and enhances carrier transport, improving device performance, compared to IGZTO/SiO 2 TFT. The mobility of these two devices is as high as 39.8 cm 2 V −1 s −1 and 46.5 cm 2 V −1 s −1 , respectively, with threshold voltages as low as −0.63 V and 0.33 V, and sub-threshold swings as low as 0.16 V decade −1 and 0.098 V decade −1 , respectively. The high- k gate insulating layer IGZTO TFTs prepared have broad application prospects in the fields of new displays and flexible electronics.