Electrical and optical properties of Al-doped ZnO films deposited by hollow cathode gas flow sputtering

Al-doped ZnO (AZO) films were deposited on glass by hollow cathode gas flow sputtering using Zn–Al alloy targets. Sputtering power for all the depositions was fixed at 1500 W. Resistivities of 0.81–1.1 × 10− 3 Ω cm were obtained for AZO films deposited at room temperature with an O2 flow from 38 to 50 standard cubic centimetre/minute (SCCM), while static deposition rates were almost constant at 270–300 nm/min. On the other hand, lower resistivities of 5.2–6.4 × 10− 4 Ω cm were obtained for AZO films deposited at 200 °C with an O2 flow from 25 to 50 SCCM, while the static deposition rates were almost constant at 200–220 nm/min. Average transmittances in the visible light region were above 80% for both sets of films.