Process development of inverted‐staggered amorphous InGaZnO thin‐film transistors with wet‐etched electrodes

Abstract Process development of inverted‐staggered amorphous InGaZnO thin‐film transistors (a‐IGZO TFTs) with wet‐etched electrodes was employed in this paper. Five metals (Al, Cu, Ti, Ta, and Cr) as well as various etchants were comparatively investigated, indicating H 2 O 2 based solution etched Ta films were good candidates for the wet‐etched electrodes of a‐IGZO TFTs. The aforementioned findings along with other improving attempts successfully established inexpensive processing steps and conditions with which stable a‐IGZO TFTs were finally fabricated. The device performance was reasonably good enough (μ FE of 6.0 cm 2 /V·s, V th of 2.5 V, SS of 1.8 V/decade, and I on /I off of 10 6 ) to meet the requirements of applications especially for small‐sized flat panel displays.