Al-doped ZnO films deposited by magnetron sputtering: effect of sputtering parameters on the electrical and optical properties

Aluminum-doped zinc oxide (AZO) thin films were prepared by magnetron sputtering method. The influences of deposition pressure, substrate temperature, Ar flow rate and film thickness on optical and electrical properties were investigated using ultraviolet-visible (UV-Vis) spectrometer and Hall measurements. The experimental results revealed that a low resistivity, smaller than 4 × 10^-4 Ω·cm, was obtained when the deposition pressure was smaller than 0.67 Pa and substrate temperature about 200 °C. Ar flow rate had a small influence on the resistivity but a big influence on the transparency at near infrared range (NIR). We obtained optimized AZO thin films with high ponductivity and transparency at low deposition pressure, small Ar flow and appropriate temperature (around 200 °C). The etching behavior of the AZO thin films deposited at the different Ar flow rates was also studied in this paper. The results show that Ar flow rate is a very important factor affecting the etching behavior.