Patent ID: 7646442

Claim:
A liquid crystal display device having a switching element in a pixel portion and a CMOS element in a driving portion, comprising: a substrate; a gate electrode on the substrate; a gate insulating layer on the gate electrode; a polycrystalline silicon layer on the gate insulating layer, the polycrystalline silicon layer having an active region in a central portion corresponding to the gate electrode and an ohmic contact region at side portions of the active region; an interlayer insulating layer having a set of contact holes for contacting the polycrystalline silicon layer at the side portions, the interlayer insulating layer entirely contacting the polycrystalline silicon layer in the active region without an intervening layer; source and drain electrodes spaced apart from each other directly on the interlayer insulating layer, the source and drain electrodes contacting the polycrystalline silicon layer through the set of contact holes; and a pixel electrode directly on the drain electrode, wherein ends of the interlayer insulating layer coincide with ends of the polycrystalline silicon layer, and wherein ends of the source and drain electrodes are disposed within the ends of the interlayer insulating layer.