Sun-Young Hong

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

The worlds 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 cm2/V-s, Vth 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 (Vth) 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 Vth positively and reduce Vth variation.

Determination of defect types of ZnSe-based epilayers by etch-pit configurations

Abstract Determination of defect types by etch-pit configurations was studied. A NaOH (30 mol%) etchant was found useful for etch-pit development on ZnSe-based epilayers grown on (001) GaAs. After etch-pit formation on the surface, Transmission Electron Microscopy (TEM) experiments were conducted. The etch-pits have been formed in three different configurations; regularly paired etch-pits in the horizontal direction, regularly paired etch-pits in the vertical direction and an array of single etch-pits in the 〈110〉 and 〈100〉 directions which result from Frank-type stacking faults, Shockley-type stacking faults and threading dislocation segments, respectively.