Liquid crystal display device having a contact hole having an undercut shape

A method for fabricating a liquid crystal display (LCD) device, the method comprising:

• preparing a substrate;
• forming a gate line arranged in one direction along with a pixel electrode on the substrate;
• forming a data line crossing the gate line to define a pixel area;
• forming a TFT at the crossing of the gate line and the data line;
• stacking a first insulating film formed of a first silicon nitride film with rich nitrogen and a second insulating film formed of a second silicon nitride film with poor nitrogen on the entire surface of the substrate including the pixel electrode and the TFT;
• patterning the second insulating film and the first insulating film to form a contact hole having an undercut shape exposing the pixel electrode and the TFT, wherein a width of the contact hole adjacent to the interface between the first and second insulating films is greater than a width of the contact hole adjacent to an upper surface of the second insulating film and a width of the contact hole adiacent to a lower surface of the first insulating film;
• forming a transparent conductive layer on the second insulating film including the contact hole to form a pixel electrode connection pattern connected with the pixel electrode and the TFT within the contact hole having an undercut shape;
• forming a photosensitive film on the transparent conductive layer including the pixel electrode connection pattern to a first photosensitive film pattern for covering completely the pixel electrode connection pattern;
• and
• patterning the photosensitive film to form a second photosensitive film pattern on the transparent conductive layer;
• and
• patterning the transparent conductive layer to form a plurality of common electrodes separately on the second insulating film.