Hydrogenated IGZO thin-film transistors using high-pressure hydrogen annealing

Abstract

Hydrogenation of thin-film indium-gallium-zincoxide (IGZO) is carried out by applying a high-pressure hydrogen annealing (HPHA) process under 5-atm pressure at different temperatures of 260 degrees C, 270 degrees C, and 280 degrees C. The HPHA effectively increases the carrier concentration and the Hall mobility up to similar to 10(19) cm(-3) and similar to 6.4 cm(2)/Vs, respectively. The HPHA-IGZO films exhibit smoother surfaces as compared with the as-grown films. The HPHA performs at a temperature of 260 degrees C that greatly enhances the electrical characteristics of IGZO TFTs, leading to a saturation field effect mobility of 7.4 cm(2)/Vs, a subthreshold slope of 0.37 V/decade, a threshold voltage of 2.2 V, and an I-ON/I-OFF of 2.0 x 10(6).