42.2: World's Largest (15‐inch) XGA AMLCD Panel Using IGZO Oxide TFT

Abstract

Abstract The world's largest (15‐inch) XGA active matrix liquid crystal display (AMLCD) panel made with IGZO TFTs (W/L=29.5/4 μm) was fabricated and evaluated with the field effective mobility of 4.2±0.4 cm 2 /V‐s, V th of −1.3±1.4V and sub‐threshold swing (SS) of 0.96±0.10 V/dec. for a manufacturing‐oriented process, the main factors affecting threshold voltage (V th ) of the IGZO thin film transistors (TFT) are investigated. On the glass surface, thicker regions of IGZO film have a negative threshold voltage shift. A dry etching process of molybdenum source and drain (S/D) causes negative shift of the average threshold voltage compared to wet etching in the bottom gate back channel etched TFTs. However, optimization of SiOx passivation and subsequent annealing shift average V th positively and reduce V th variation.