Patent ID: 7940362

Claim:
A method of manufacturing an in-plane switching liquid crystal display having thin film transistors on a substrate, scan lines and signal lines connected to the thin film transistors and longitudinally and latitudinally crossing each other, and common wiring formed by the same layer as the scan lines and generating electric fields substantially parallel to the substrate between a common electrode connected to the common wiring and covering at least the signal lines partially via an interlayer insulating film formed on at least source and drain electrodes of the thin film transistors, and a pixel electrode connected to the thin film transistors, wherein: the interlayer insulating film is formed by an inorganic insulating film, and a part of a common electrode contact hole for connecting the common wiring and the common electrode via the interlayer insulating film and a gate insulating film formed under the source and drain electrodes to each other is formed by at least dry etching, a thickness of the interlayer insulating film being greater than a thickness that is etched in the interlayer insulating film and the gate insulating film by the dry etching to form the common electrode contact hole, wherein wet-etching is performed in a region which is enclosed by the part of the common electrode contact hole that is dry etched.