Effect of surface roughness on electrical characteristics in amorphous InGaZnO thin-film transistors with high-κ Sm2O3 dielectrics

► We investigated the effect of surface roughness on the electrical characteristics in high-κ Sm2O3 a-IGZO TFT devices. ► The Sm2O3 a-IGZO TFT device annealed at 200 °C exhibited better electrical characteristics than other temperatures. ► The reliability of a Sm2O3 a-IGZO TFT can be improved by oxygen annealing at low temperature.