Structural Analysis and Electrical Properties of Carbon-doped Yttrium Titanate (YTiO<sub>x</sub>) Thin Films Deposited by Mist CVD

In this study, carbon-doped Y2Ti2O7 and TiO2 22% - 1/2 (Y2O3) 78% (TiO2 22%-YTO) thin films were fabricated using mist CVD method under atmospheric pressure, and their structural analysis and electrical characteristics were evaluated. These films were formed using a low-temperature process with maximum heat treatment at 430°C and exhibited memory switching properties based on metal-insulator transition (MIT). The fabricated devices showed an initial low-resistance metallic state (Born-on characteristic) and demonstrated non-polar switching behavior, transitioning to a high-resistance insulating state when a voltage of approximately 0.7 V was applied. Furthermore, TiO2 22%-YTO maintained similar switching performance at 200°C as at room temperature, confirming operation over a wide temperature range. SIMS analysis confirmed approximately 0.4% carbon doping in the films, which is believed to create impurity levels that enable metal-insulator transitions in Mott-Hubbard insulators. The material system developed in this research is promising for applications in correlated electron random access memory (CeRAM) that operates at low voltages over a broad temperature range.