Influence of deposition pressure on properties of ZnO: Al films fabricated by RF magnetron sputtering

Abstract

Transparent conductive aluminum doped zinc oxide (ZnO:Al, AZO) films were prepared on glass substrates by rf (radio frequency) magnetron sputtering from ZnO: 3wt% Al₂O₃ ceramic target. The effect of argon gas pressure (P _Ar) was investigated with small variations to understand the influence on the electrical, optical and structural properties of the films. Structural examinations using X-ray diffraction (XRD) and scanning electron microscopy (SEM) showed that the ZnO:Al thin films were (002) oriented. The resistivity values were measured by four-point probe with the lowest resistivity of 5.76×10^-4 Ω·cm (sheet resistance=9.6 Ω/sq. for a thickness=600 nm) obtained at the P _Ar of 0.3 Pa. The transmittance was achieved from ultraviolet-visible (UV-VIS) spectrophotometer, 84% higher than that in the visible region for all AZO thin films. The properties of deposited thin films showed a significant dependence on the P _Ar.

Keywords

magnetron sputtering / Al-doped zinc oxide / argon pressure / properties

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