Effects of high-temperature thermal annealing on the electronic properties of In-Ga-Zn oxide thin films

Abstract

Indium gallium zinc oxide (IGZO) thin films were deposited by radio-frequency magnetron sputtering at room-temperature. Then, thermal annealing was conducted to improve the structural ordering. X-ray diffraction and high-resolution transmission electron microscopy demonstrated that the as-deposited IGZO thin films were amorphous and crystallization occurred at 800 and 950 °C. As a result of crystallization at high temperature, the carrier concentration and the Hall mobility of IGZO thin films were sharply increased, which could be ascribed to the increased oxygen vacancies and improved structural ordering of the thin films.

Rapid thermal annealing effect on performance variations of solution processed indium–gallium–zinc-oxide thin-film transistors

“…This means that despite the high temperature annealing of up to 600 ○ C of the samples in any ambient atmosphere of He, Ar, N 2, and O 2 , there is no observable phase change, and the IGZO thin film exhibits an amorphous phase, which is consistent with prior results. [11][12][13] Therefore, the phase change in IGZO TFTs can be excluded to analyze the performance variations depending on the different molecular concentrations, annealing temperatures, and ambients. Figures 2(a)-2(d) show atomic force microscopy (AFM) images of thin active layer a-IGZO TFTs with He, N 2 , O 2 , and Ar annealing ambients, respectively (annealing temperature was 500 ○ C).…”