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 lFE of >11.1 ㎠/V s and good stability based in large falling-rate (RF) of 0.18 eV/V, trapping-time (τ) of 1.0 x 107 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.