Comparing Microstructures of ITO Sputtering Targets Prepared by Tin Doped Indium Oxide Powders and In2O3-SnO2 Mixed Powders

Indium Tin Oxide sputtering target (ITO) is widely used in the formation of electrically transparent thin films, which adopt direct current magnetron sputtering process for electrodes in flat panel displays, solar cells, gas sensors and so on. In order to improve ITO thin film property, ITO sputtering target requires high purity, homogeneous microstructure, high density and high electrical conductivity. In the present paper, ITO sputtering targets were fabricated using In2O3-SnO2 mixed powders and tin doped indium oxide powders. Meanwhile, their discrepancies in microstructure and sintering mechanism, especially grain size distribution, grain morphology, major element distribution and sintering rate, were studied. The results show that the sintering rate of the mixed powders is faster than that of the doped powders, but it is difficult to obtain homogeneous microstructure for the mixed powders. In contrast, it is easy to obtain the ITO sputtering target with homogeneous microstructure using the doped powders, under the condition that the decomposition of indium oxide is inhibited in process of sintering. These results are helpful to fabricate ITO sputtering target with good microstructure, while decrease nodulation and improve production efficiency.