Array substrate, method of manufacturing the same and method of crystallizing silicon

1. A method of manufacturing an array substrate comprising:

forming a poly silicon pattern having at least one block on a base substrate, grains formed in each block extended in a plurality of directions;

forming a gate insulating layer on the base substrate covering the poly silicon pattern;

forming a gate electrode on the gate insulating layer, the gate electrode overlapping the poly silicon pattern;

forming an insulating interlayer covering the gate insulating layer and the gate electrode;

forming a first contact hole through which a first end portion of the poly silicon pattern is exposed and forming a second contact hole through which a second end portion of the poly silicon pattern is exposed in the insulating interlayer and the gate insulating layer;

forming a source electrode and a drain electrode, the source and drain electrodes making contact with the first and second end portions through the first and second contact holes, respectively; and

forming a pixel electrode electrically connected to the drain electrode,

wherein each of the at least one block is divided into a first grain region, a second grain region, a third grain region, and a fourth grain region, and each of the first, second, third, and fourth grain regions has a substantially triangular shape.

2. The method of claim 1 , wherein forming a poly silicon pattern includes

forming an amorphous silicon layer on the base substrate;

arranging a mask on the amorphous silicon layer, the mask including a transmitting portion and a blocking portion;

irradiating a laser beam on a first melting area of the amorphous silicon layer corresponding to the transmitting portion to melt the first melting area;

shifting the mask by a width of the transmitting portion; and

irradiating the laser beam on a second melting area of the amorphous silicon layer corresponding to the transmitting portion to melt the second melting area and form a poly silicon layer.

3. The method of claim 2 , wherein forming the poly silicon pattern further includes patterning the poly silicon layer through a photolithography process.

4. The method of claim 1 , wherein each of the at least one block has a substantially square shape.

5. The method of claim 4 , wherein grains formed in the first grain region and the third grain region are extended in a horizontal direction of the array substrate, and grains formed in the second and fourth grain regions that are adjacent to the first grain region are extended in a longitudinal direction of the array substrate.

6. The method of claim 1 , wherein a width of each of the at least one block is no more than a distance between the source electrode and the drain electrode.

7. The method of claim 1 , prior to the forming the pixel electrode, further comprising:

forming a protecting layer on the insulating interlayer; and

forming a third contact hole through which the drain electrode is partially exposed in the protecting layer,

wherein forming the pixel electrode electrically connected to the drain electrode includes connecting the pixel electrode to the drain electrode through the third contact hole.

8. A method of crystallizing silicon comprising:

forming an amorphous silicon layer on a base substrate;

arranging a mask on the amorphous silicon layer, the mask including a transmitting portion having a substantially square shape and a blocking portion;

irradiating a laser beam on a first melting area of the amorphous silicon layer corresponding to the transmitting portion to melt the first melting area so that a poly silicon grain grows from an interface between the first melting area and a non-melting area toward an interior of the first melting area, the non-melting area corresponding to the blocking portion;

shifting the mask by a width of the transmitting portion; and

irradiating the laser beam on a second melting area of the amorphous silicon layer corresponding to the transmitting portion to melt the second melting area so that a poly silicon grain grows from an interface between the first and second melting areas towards an interior of the second melting area to form a poly silicon layer,

wherein each melting area is divided into a first grain region, a second grain region, a third grain region, and a fourth grain region, and each of the first, second, third, and fourth grain regions has a substantially triangular shape.

9. The method of claim 8 , wherein a first grain extended in a first direction is formed in the first grain region,

a second grain extended in a second direction that is substantially perpendicular to the first direction is formed in the second grain region,

a third grain extended in a third direction that is substantially opposite to the first direction is formed in the third grain region, and

a fourth grain extended in a fourth direction that is substantially opposite to the second direction is formed in the fourth grain region.

10. The method of claim 8 , wherein the transmitting portion has substantially a same shape and size as a shape and size of the blocking portion.