It was demonstrated that the layered structure of SiOx and SiNx is a good candidate to be gate insulator and passivation layers in IGZO TFT. However, this multi-layered structure could introduce issues of transmittance at aperture area in single glass of TFT side based optics physics. It is a good solution to improve the transmittance via optmizing structures of GI and PV layers, which could be adopted in IGZO-TFT LCD displays.