Liquid crystal display device having a composite data line with a line opening exposing the top surface and sidewalls

A method for fabricating an LCD device, the method comprising:

• forming a gate line and a gate electrode on a substrate;
• sequentially forming a gate insulating layer, a semiconductor layer, and a metal layer overlying the substrate and the gate line and the gate electrode;
• forming source and drain electrodes and a data line:
• forming a passivation layer overlying the source and drain electrodes, and forming a mask pattern on passivation layer, the mask having an opening over a portion of the data line;
• etching the passivation layer using the mask pattern and etching the semiconductor layer using the mask pattern and a portion of the data line as an etch mask to form a composite layer in which the semiconductor layer and the portion of the data line have substantially the same line width;
• forming contact holes in the passivation layer;
• forming a pixel electrode overlying the passivation layer;
• and
• forming a data line protection layer covering the composite layer, the data protection layer formed on the same layer as the pixel electrode where the data line crosses over the gate line.