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Journal of Nanomaterials
Volume 2014 (2014), Article ID 347858, 5 pages
Research Article

Temperature Effects on a-IGZO Thin Film Transistors Using HfO2 Gate Dielectric Material

Department of Electronic Engineering, National United University, Miaoli 36003, Taiwan

Received 18 January 2014; Revised 16 June 2014; Accepted 20 June 2014; Published 6 July 2014

Academic Editor: Kaushal Kumar

Copyright © 2014 Yu-Hsien Lin and Jay-Chi Chou. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.


This study investigated the temperature effect on amorphous indium gallium zinc oxide (a-IGZO) thin film transistors (TFTs) using hafnium oxide (HfO2) gate dielectric material. HfO2 is an attractive candidate as a high-κ dielectric material for gate oxide because it has great potential to exhibit superior electrical properties with a high drive current. In the process of integrating the gate dielectric and IGZO thin film, postannealing treatment is an essential process for completing the chemical reaction of the IGZO thin film and enhancing the gate oxide quality to adjust the electrical characteristics of the TFTs. However, the hafnium atom diffused the IGZO thin film, causing interface roughness because of the stability of the HfO2 dielectric thin film during high-temperature annealing. In this study, the annealing temperature was optimized at 200°C for a HfO2 gate dielectric TFT exhibiting high mobility, a high ratio, low current, and excellent subthreshold swing (SS).