The interfacial reaction between ITO and silicon nitride deposited by PECVD in fringe field switching device

In fringe field switching (FFS) device, the distance (l) between electrodes should be smaller than the cell gap (d) to generate fringe field. In order to increase the transmittance, common and pixel electrodes which are separated with the insulator should be transparent conductive materials. When the silicon-nitride by plasma enhanced chemical vapor deposition using SiH4 gas is deposited on ITO in FFS device, the radical containing hydrogen causes the reduction of the indium-oxide to metallic indium on the film surface and finally the decrease of transmittance in visible range. To prohibit the reduction of In, the reduction of SiH4 flow rate is needed. Therefore we suggest the two-step process in depositing the SiNx consisting of a buffer-SiNx layer and a bulk-SiNx layer.