Transport Properties of RF-Magnetron Sputtered AZO Thin Films: The Effect of Processes Parameters During and Post Deposition

Abstract

Aluminum doped zinc oxide (AZO) is an n-type conductive oxide which is widely used as a transparent electrode in a photovoltaic device. In the present study, AZO thin films have been deposited on glass substrates via RF magnetron sputtering. The effect of deposition parameters such as RF power, substrate-temperature and working pressure on the electrical and structural properties of the films has been studied. With an increase in RF power, substrate-temperature and a decrease in the working pressure, the film resistivity decreases. For example when the substrate-temperature was raised from 50 to 500 °C, the resistivity decreased by three-orders of magnitude viz. from $3 \times 10^{1} \Omega \cdot$cm to $2.78 \times 10^{-2} \Omega \cdot$cm. AZO thin film with resistivity as low as $6.59 \times 10^{-3} \Omega \cdot$cm has been achieved with RF power of 100 W, substrate-temperature of 350 °C and a working pressure of $1 \times 10^{-3}$ mbar.