Correlation between electrical and structural changes in amorphous ITO films

초록

We investigated the temperature-dependent resistance, structural properties, and chemical state of amorphous ITO film during annealing under vacuum using in-situ analyses. In-situ resistance measurement revealed a sharp increase in resistance, reaching a maximum at approximately 180 degrees C and decreasing with a further increase in annealing temperature. In-situ X-ray diffraction confirmed the onset of crystallization of the amorphous ITO film at the temperature where the resistivity increased sharply. From the in-situ XPS analysis, we found no change in chemical states, such as oxygen vacancy or the formation of Sn4+. In the Hall effect measurement, we confirmed a significant decrease in mobility at the ITO film annealed in vacuum at 175 degrees C. This indicates the grain boundaries formed by the crystallization of ITO increase the electron scattering, causing a sharp increase in resistance at 180 degrees C. Our findings suggest that structural changes primarily drove the change in electrical properties of amorphous ITO during annealing. This study highlights the importance of real-time monitoring in understanding the dynamic change in ITO film and provides a comprehensive understanding of the structural and electrical transitions during crystallization.

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