Pulsed electron beam deposition of transparent conducting Al-doped ZnO films

Abstract

Good quality transparent conducting Al-doped ZnO films were deposited on quartz substrates from a high purity target using pulsed electron deposition (PED). Two series of films were made, one deposited at room temperature but at four pressures, viz., 0.7, 1.3, 2.0 and 2.7Pa of oxygen and one deposited at 1.3Pa oxygen pressure but at the substrate temperature ranged from room temperature to 600°C. In order to evaluate the effect of substrate temperature and oxygen pressure on the properties of obtained films, various characterization techniques were employed including X-ray diffraction, stylus profiler, scanning electron microscope, optical spectrophotometer and electrical resistivity. For the first series films, the optimal oxygen pressure of 1.3Pa was found to bring about the appropriate energetic deposition atoms which results in the best crystallinity. For the second series films, the lowest resistivity was obtained in the film grown at 400°C. An attempt was made to reduce the resistivity by lowering the oxygen pressure to 0.5Pa which was the lower limit of working pressure of the PED system. The obtained results indicate that PED is a suitable technique for growing transparent conducting ZnO films.