Structural and electrical characteristics of high-κ Er2O3 and Er2TiO5 gate dielectrics for a-IGZO thin-film transistors

Fa-Hsyang Chen; Jim-Long Her; Yu-Hsuan Shao; Yasuhiro H Matsuda; Tung-Ming Pan

doi:10.1186/1556-276X-8-18

Structural and electrical characteristics of high-κ Er2O3 and Er2TiO5 gate dielectrics for a-IGZO thin-film transistors

Nanoscale Res Lett. 2013 Jan 8;8(1):18. doi: 10.1186/1556-276X-8-18.

Authors

Fa-Hsyang Chen¹, Jim-Long Her, Yu-Hsuan Shao, Yasuhiro H Matsuda, Tung-Ming Pan

Affiliation

¹ Department of Electronics Engineering, Chang Gung University, 333, Taoyuan, Taiwan. tmpan@mail.cgu.edu.tw.

Abstract

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.