Plasma treatment effect on charge carrier concentrations and surface traps in a-InGaZnO thin-film transistors

Abstract

Various plasma treatment effects such as oxygen (O-2), nitrogen (N-2), and argon (Ar) on amorphous indium gallium zinc oxide thin-film transistors (a-IGZO TFTs) are investigated. To study oxygen stoichiometry in a-IGZO TFTs with respect to various plasma environments, X-ray photoelectron spectroscopy was employed. The results showed that oxygen vacancies were reduced by O-2 and N-2 plasmas while they were increased after Ar plasma treatment. Additionally, the effects of plasma treatment on trap distribution in bulk and surface channels were explored by means of low-frequency noise analysis. Details of the mechanisms used for generating and restoring traps on the surface and bulk channel are presented. (C) 2014 AIP Publishing LLC.