Silicon crystallization apparatus and silicon crystallization method thereof

A silicon crystallization method, which comprises:

• providing a silicon crystallization apparatus including an optical device for generating laser beams, a stage for fixing a substrate having silicon deposited thereon, and for being rotatably and movably provided with the substrate in a horizontal direction, and a sensing device provided in the optical device, the sensing device facing toward an edge of the substrate to directly sense the edge of the substrate;
• forming an amorphous silicon layer over an entire surface of the substrate defined as a display area and a non-display area;
• fixing the substrate to the stage;
• aligning the substrate by sensing the substrate fixed on the stage with the sensing device, and moving and/or rotating the stage;
• forming alignment keys on predetermined portions of the non-display area by correspondingly providing a mask for formation of alignment key above the substrate;
• crystallizing the amorphous silicon on predetermined portions of the display area by correspondingly placing a first crystallization mask above the substrate;
• and
• crystallizing the amorphous silicon of the non-display area by correspondingly placing a second crystallization mask above the substrate.