Liquid crystal display device having polycrystalline silicon thin film transistor and method of fabricating the same

A method of fabricating a liquid crystal display (LCD) device, comprising;

• forming at least an alignment key on a first substrate, having a first region and a second region, wherein the alignment key is substantially located in the second region;
• forming an amorphous silicon layer on the alignment key;
• crystallizing a predetermined portion of the amorphous silicon layer using the alignment key as a reference;
• patterning the amorphous silicon layer using the alingment key as a reference to form a polycrystalline silicon layer, when the polycrystalline silicon layer is formed from the predetermined portion of the amorphous silicon layer;
• forming a gate insulating layer on the semiconductor layer;
• forming a gate electrode on the gate insulating layer using the alignment key as reference;
• forming an interlayer insulating layer on the gate electrode;
• forming source and drain electrodes on the interlayer insulating layer;
• forming a passivation layer on the source and drain electrodes;
• forming a pixel electrode on the passivation layer;
• forming a common electrode on a second substrate;
• attaching the first and second substrates such that the pixel electrode faces the common electrode;
• and
• forming a liquid crystal layer between the pixel elecrode and the common electrode.