Method for fabricating array substrate of liquid crystal display device

A method for fabricating an array substrate of an LCD device comprising:

• depositing a conductive layer on a substrate, and simultaneously forming a gate line, a gate electrode and a pixel electrode by photolithography using a first mask;
• forming a gate insulating layer, a semiconductor layer and a photoresist on an entire surface of the substrate including the gate line, and patterning the gate insulating layer and the semiconductor layer to remain on the gate electrode and the gate line by patterning the photoresist with a diffraction exposure process using a second mask;
• selectively removing the semiconductor layer above the gate line after ashing the photoresist;
• and
• depositing a metal layer on the entire surface of the substrate including the semiconductor layer, and forming a data line and source/drain electrodes using a third mask.