Effects of Substrate Heating on the Amorphous Structure of InGaZnO Films and the Electrical Properties of Their Thin Film Transistors

This study examines the effects of substrate heating on the amorphous structure of InGaZnO 4 (IGZO) films and the device performance of transistors produced from these films. By combining high-resolution transmission electron microscopy (HRTEM) and energy-filtered selected area electron diffraction (EF-SAED), we found that the atomic order improved significantly for the IGZO films deposited on a heated substrate, compared to the samples deposited on an unheated substrate and postannealed. Measurement of the electrical characteristics of the transistors discloses that the amorphous structure changes induced by substrate heating profoundly influenced the overall device performance, leading to a substantial increase in electron mobility.