Properties of AZO thin films prepared by stationary and rotating RF magnetized plasma sputtering source

Abstract

The aluminum-doped zinc oxide (AZO) films were deposited with a star-shaped plasma using a high-density radio frequency (RF) magnetized sputtering source to develop well-consistent target utilization. The deposited AZO film characteristics were investigated using stationary and rotational modes with a velocity of 40 rpm, Ar pressure of 1.0 Pa, and RF power of 40 W with a deposition time of 1.0 h. The deposition rate profile of stationary mode with a roughness of ±30.18% was more fluctuating than that of rotational mode with a roughness of ±10.90%. The lowest electrical resistivities of the AZO films were obtained as 3.8 × 10−4 and 3.6 × 10−4 Ω cm at r = 0 mm for the stationary and rotational modes, respectively. According to the AFM and SEM results, the surface profile of the rotational mode grown AZO film was more uniform and smoother than that of the stationary mode. The intensity of x-ray diffraction peaks (002) of the grown AZO film was decreased from the center to the edge of the vessel. Most of the films showed two broad Raman peaks at about 274 and 575 cm−1, representing additional mode and longitudinal optical phonons of the wurtzite ZnO crystal. All the AZO films showed a high transmittance in the visible range, and the average transmittance of the AZO films in the visible range was ∼84%.