According to an embodiment of inventive concepts, a substrate dicing method may include forming reformed patterns in a substrate using a laser beam, grinding a bottom surface of the substrate to thin the substrate, and expanding the substrate to divide the substrate into a plurality of semiconductor chips. The forming of the reformed patterns may include forming a first reformed pattern in the substrate and providing an edge focused beam to a region crossing the first reformed pattern to form a second reformed pattern in contact with the first reformed pattern.