Al doped ZnO (ZnO:Al-AZO) thin films have been investigated for use as photovoltaic cells or as transparent conductive oxide (TCO) of displays, because AZO has good electrical and optical properties. In this study, ZnO:Al (AZO) thin films were prepared on substrates at temperatures room temperature, 100 degrees C and 200 degrees C by a facing target sputtering (FTS) system. The electrical and optical properties of the AZO thin films were investigated by a four-point probe (Changmin) and a UV/VIS spectrometer (UP). Also the roughnesses of AZO thin films were investigated as a function of substrate temperature. AZO thin films were deposited with a transmittance of over 80% and the resistivity was reduced from 1.36x10(-3) Omega.cm to 4x10(-4) Omega.cm by increasing the substrate temperature from room temperature to 200 degrees C. In particular, we could obtain a resistivity of U 10(-4) Omega.cm in an AZO thin film prepared at a working pressure 133 mPa, an input current 0.4A and a substrate temperature of 200 degrees C.

Keywords: facing target sputtering; AZO; TCO; resistivity