Structural and electrical characteristics of high-κ Er2O3 and Er2TiO5 gate dielectrics for a-IGZO thin-film transistors
1 Department of Electronics Engineering, Chang Gung University, 333, Taoyuan, Taiwan
2 Division of Natural Science, Center for General Education, Chang Gung University, 333, Taoyuan, Taiwan
3 Institute for Solid State Physics, University of Tokyo, 277–8581, Chiba, Japan
Nanoscale Research Letters 2013, 8:18 doi:10.1186/1556-276X-8-18Published: 8 January 2013
In this letter, we investigated the structural and electrical characteristics of high-κ Er2O3 and Er2TiO5 gate dielectrics on the amorphous indium-gallium-zinc-oxide (a-IGZO) thin-film transistor (TFT) devices. Compared with the Er2O3 dielectric, the a-IGZO TFT device incorporating an Er2TiO5 gate dielectric exhibited a low threshold voltage of 0.39 V, a high field-effect mobility of 8.8 cm2/Vs, a small subthreshold swing of 143 mV/decade, and a high Ion/Ioff current ratio of 4.23 × 107, presumably because of the reduction in the oxygen vacancies and the formation of the smooth surface roughness as a result of the incorporation of Ti into the Er2TiO5 film. Furthermore, the reliability of voltage stress can be improved using an Er2TiO5 gate dielectric.