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 Sm
₂
TiO
₅
gate dielectrics. The high-κ Sm
₂
TiO
₅
α-IGZO TFT after annealing at 400°C exhibited very good electrical characteristics, such as a high I
_on/off
ratio of 5.27×10
⁷
, a high field-effect mobility of 27.8 cm
²
/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 Sm
₂
O
₃
film, resulting in the formation of good Sm
₂
TiO
₅
gate dielectric and low density of interface states at the oxide/channel interface.