Open Access Nano Express

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

Fa-Hsyang Chen1, Jim-Long Her2, Yu-Hsuan Shao1, Yasuhiro H Matsuda3 and Tung-Ming Pan1*

Author affiliations

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

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Citation and License

Nanoscale Research Letters 2013, 8:18  doi:10.1186/1556-276X-8-18

Published: 8 January 2013

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.

Keywords:
Amorphous InGaZnO; Thin-film transistor; Er2O3; Er2TiO5