Structural and electrical characteristics of high-κ Sm2TiO5 gate dielectrics for InGaZnO thin-film transistors

In this study, we developed an amorphous indium-gallium-zinc oxide (α-IGZO) thinfilm transistor (TFT) incorporating high-κ Sm₂TiO₅ gate dielectrics. The high-κ Sm₂TiO₅ α-IGZO TFT after annealing at 400°C exhibited very good electrical characteristics, such as a high I_on/off ratio of 5.27×10⁷, a high field-effect mobility of 27.8 cm²/V-sec, a low threshold voltage of 0.2 V, and a low subthreshold swing of 136 mV/decade. These results are probably due to the incorporation of Ti into the Sm₂O₃ film, resulting in the formation of good Sm₂TiO₅ gate dielectric and low density of interface states at the oxide/channel interface.