Effect of Oxygen Partial Pressure and Sintering Temperature on the Evaporation of Elements during Sintering in In-Sn-Zn-O Transparent Conducting Oxide Systems

An amorphous In-Sn-Zn-O (ITZO) thin film has high electrical properties and is less prone to cracking in repeated bending, which is advantageous for application to flexible display panels.When ITZO sputtering target is sintered at high temperatures, the original compositions often deviate from the stoichiometry due to volatilization of In, Sn and Zn.In order to minimize the evaporation, targets have been sintered in high oxygen atmospheres.We investigate the volatile-induced compositional deviation of the ITZO samples after sintering.An electron probe micro-analyzer (EPMA) depth profile of the composition and thermogravimetric weight loss at high temperature were analyzed.The results showed that the sintering of ITZO at high oxygen partial pressure is very effective to suppress the volatilization of In, Sn, and Zn.The electrical and optical characteristics of the ITZO thin films are also analyzed.