The physical properties of AZO films deposited by RF magnetron sputtering in hydrogen-diluted argon

The properties of AZO (98-wt% ZnO, 2-wt% Al2O3) films produced in pure Ar and Ar (98%) + H 2 (2%) (H 2 -diluted Ar) by radio-frequency (RF) magnetron sputtering were investigated as functions of the substrate temperatures. H 2 -diluted Ar improved the electrical properties of the AZO films fabricated at low substrate temperatures, but this benefit gradually diminished with increasing substrate temperature. This phenomenon was explained by O-H stretching in the Zn-O bond at low temperatures and by the formation of oxygen vacancies at high temperatures. The average optical transmission was over ~85%, and the orientation of the AZO films deposited both in pure Ar and in H 2 -diluted Ar was in the [002] direction.