Characteristics of atomic layer deposited transparent aluminum-doped zinc oxide thin films at low temperature

Abstract

Various aluminum-doped zinc oxide (AZO) films were prepared on Si substrate by atomic layer deposition (ALD) at 100 °C. The effect of the composition of AZO films on their electrical, optical characteristics, structural property and surface topography was investigated. The appearance of electrical resistivity shows their semiconducting properties. In most of the visible light band, all the AZO films present transparency of more than 80 %. Al doping suppresses the AZO film crystallization. When the Al doping concentration increases up to 3.95 at%, the AZO film has some small multicrystal grains with random orientation. Al doping improves the roughness of i-ZnO film. The root mean square (RMS) roughness of samples prepared by ALD is much smaller than that prepared by radio-frequency magnetron sputtering reported.