Correlation between the stability and trap parameters of amorphous oxide thin film transistors

Abstract

We report on the temperature dependence phenomena in stability and trap related parameters in amorphous-hafnium-indium-zinc-oxide (a-HIZO) thin film transistors (TFTs) with different Hf-ratio. The optimized 7HIZO TFT shows large mu(FE) of > 11.1 cm(2)/V s and good stability based in large falling-rate (R-F) of 0.18 eV/V, trapping-time (tau) of 1.0 x 10(7) s and small subthreshold-swing (SS) of 0.74 V/dec. Relation between thermally activated energy and Hf-ratio clearly indicated Hf acted as carrier suppressors since the increase of Hf-ratio in a-HIZO films. The Hf greatly affected the overall device performance as well as the stability. (C) 2011 Elsevier B.V. All rights reserved.