Electrical characteristics of gallium-indium-zinc oxide thin-film transistor non-volatile memory with Sm₂O₃ and SmTiO₃ charge trapping layers

In this study, we report the structural and electrical characteristics of high-κ Sm₂O₃ and SmTiO₃ charge trapping layers on an indium-gallium-zinc oxide (IGZO) thin-film transistor (TFT) for non-volatile memory device applications. The IGZO TFT non-volatile memory featuring a SmTiO₃ charge trapping layer exhibited better characteristics, including a larger memory window (2.7 V), long charge retention time (10⁵ s with charge loss <15%) and better endurance performance for program/erase cycles (10⁴), compared with a Sm₂O₃ charge trapping layer. These results can be attributed to the SmTiO₃ film possessing a high dielectric constant and deep trapping level. The high-κ SmTiO₃ is an excellent candidate for use as the trapping layer in IGZO TFT non-volatile memories.