Amorphous ITZO Thin-Film Transistors by Using Ultrasonic Spray Pyrolysis Deposition

This study demonstrates an amorphous indium–tin–zinc–oxide (a-ITZO) thin-film transistor (TFT) using an ultrasonic spray pyrolysis deposition (USPD) method. X-ray diffraction, X-ray photoelectron spectroscopy, Tauc plot, and photoluminescence spectrum are used to confirm the crystal structure, oxygen contents, energy bandgap, and the existence of oxygen deficiencies. Besides, these material characteristics are compared with a sputter-deposited ITZO film. The TFT based on the USPD-deposited ITZO shows better electrical performance than the TFT based on the sputter-deposited ITZO. In addition, the negative- /positive-bias illumination stress results indicate that the TFT based on the USPD-deposited ITZO film is more stable than the one based on the sputter-deposited ITZO.