The densification, microstructure, and electrical properties of aluminum-doped zinc oxide sputtering target for transparent conductive oxide film

摘要

AZO films are regarded as a potential substitute for ITO due to their excellent performance. To optimize the performances of AZO films, the correlation between the target and film must be clearly clarified. Therefore, how the properties, particularly the electrical ones, of the sputtering targets evolve with the sintering parameters are rarely highlighted. To develop high-quality AZO and ZnO targets, the densification, microstructure, and electrical properties of the targets were investigated in this study. The results showed that after sintering at 1100°C in air, the 2 wt% Al_2O_3 additive in ZnO results in retarded densification, the formation of ZnAl_2O_4 phase, and inferior electrical properties. However, after sintering at 1200 °C or higher temperatures, the Al_2O_3 additive leads to finer grain size, higher sintered density, and better electrical properties. In general, the AZO targets are also found to exhibit higher Hall mobility and lower carrier density than the AZO films do.