US Patent 8071985 Display device and method of manufacturing the same

The invention provides a display device having a thin film transistor and a storage capacitor storing a display signal applied to a pixel electrode through this thin film transistor on a substrate, where dielectric strength between electrodes forming the storage capacitor is enhanced for increasing the yield. In the storage capacitor, a lower storage capacitor electrode, a thin lower storage capacitor film, a polysilicon layer, an upper storage capacitor film and an upper storage capacitor electrode are layered. The polysilicon layer is formed by crystallization by laser annealing. The polysilicon layer of the storage capacitor is microcrystalline and thus the flatness of its surface is enhanced. The pattern of the polysilicon layer (storage capacitor electrode) is formed larger than the bottom portion of an opening, and the edge of its peripheral portion is located on a buffer film on the slant portion of the opening or on the buffer film on the outside of the opening.