P‐1.3: High Performance of Amorphous IGZO TFTs with Different Chemical Composition Deposited by PEALD

Amorphous InGaZnOx (a‐IGZO) thin‐film transistors (TFTs) fabricated by plasma enhanced atomic layer deposition (PEALD) are currently used in flat‐panel displays due to their beneficial properties[1]. However, the a‐IGZO TFTs with different chemical composition show a huge difference in electrical properties[2]. Therefore, the key to obtaining high‐performance IGZO TFTs is to find the appropriate chemical components, which can ensure high mobility and switching ratio, as well as low subthreshold swing and reasonable threshold voltage. Chemical bond states of a‐IGZO films were analyzed by X‐ray photoelectron spectroscopy (XPS), and reasonable chemical composition IGZO TFTs with vertically stacked InOx, ZnOx, and GaOx atomic layers exhibit excellent performances such as saturation mobility of ~ 70 cm 2 /(V°s), threshold voltage of 5.02 V, I on /I off ratio of 9.8 × 10 8 , subthreshold swing of 0.53 V/decade. This study illustrates the potential advantages of atomic layer deposition processes for the emerging semiconductor application.