A Study on the Interface Diffusion of In<sub>2</sub>O<sub>3</sub>/ITO Multilayer Thin-Film Thermocouple

In 2 O 3 /ITO multilayer thin film thermocouple is a new type of semiconductor thin-film thermocouple, which has broad application prospects. The interface diffusion between the layers is the main cause of its thermal oxidation failure. In this paper, an interface diffusion model of multilayer films is established based on Fick's second law. A sample of In 2 O 3 /ITO thin-film thermocouple was prepared, then designed and conducted high temperature test. According to the test results, the diffusion of substances between the film layers was analyzed. Based on the established interface diffusion model, a simulation calculation is carried out. The influence of interface diffusion on the life of In 2 O 3 and ITO sensitive layer was quantitatively analyzed.