Method for crystallizing silicon

1. A method for crystallizing silicon, the method comprising:

forming an amorphous silicon layer on a substrate;

aligning a mask above the substrate, the mask being divided into a plurality of blocks, each block having at least two transmission patterns, the transmission patterns of one block and the transmission patterns of another adjacent block being complimentary with each other and the mask including at least two diffraction patterns disposed between the transmission patterns;

forming a first crystallization region on the amorphous silicon layer by irradiating a laser beam through the transmission patterns of the mask; and

displacing the substrate or the mask by a predetermined distance and irradiating a laser beam onto the substrate to recrystallize the crystallization region using the laser beam that passes through the diffraction patterns, and forming a second crystallization region using the laser beam that passes through the transmission patterns,

wherein the diffraction patterns include one of at least two slits and at least two or more transmission holes.

2. The method according to claim 1 , wherein in the displacing the substrate or the mask, one displacement corresponds to half a size of the mask.

3. The method according to claim 1 , wherein the transmission patterns of the mask has a width that is less than or equal to twice a maximum growth length of a grain that can grow with a single laser beam irradiation.

4. The method according to claim 1 , wherein at least two transmission holes have a shape selected from one of a rectangle, a circle and a triangle.

5. The method according to claim 1 , wherein at least two diffraction patterns are spaced apart by a predetermined interval from at least two transmission patterns adjacent to at least two diffraction patterns.

6. The method according to claim 1 , wherein the laser beam that passes through the two or more transmission patterns of the mask has an energy density that is greater than an energy density of the laser beam that passes through at least two diffraction patterns.

7. The method according to claim 1 , wherein at least two transmission patterns are formed in a stripe pattern.

8. The method according to claim 1 , wherein at least two transmission patterns have a width that is greater than a width of at least two diffraction patterns.

9. The method according to claim 1 , wherein the laser beam is irradiated onto the mask with an equal energy.

10. The method according to claim 1 , wherein at least two diffraction patterns of the mask diffract the laser beam when the laser beam passes through at least two diffraction patterns.