Method of improving polysilicon film crystallinity

1 . A mask for recrystallization in a sequential lateral solidification (SLS) process comprising:

a main pattern portion to define a pattern of a laser beam scanning the amorphous silicon film to transform the amorphous silicon film into a polysilicon film; and

a compensating pattern portion adjacent to the main pattern portion for adjusting the energy of the laser beam scanning the polysilicon film to improve grain shape thereof.

2 . The mask of claim 1 , wherein the compensating pattern portion is transparent.

3 . The mask of claim 1 , wherein the compensating pattern portion is translucent.

4 . The mask of claim 1 , wherein the compensating pattern portion comprises a dummy pattern.

5 . The mask of claim 1 , wherein the energy ratio of the laser beam adjusted by the compensating pattern portion to that through the main pattern portion is ⅓˜⅗.

6 . A method for improving polysilicon film crystallinity in a sequential lateral solidification (SLS) process, comprising:

providing an amorphous silicon film;

providing a mask having a main pattern portion and a compensating pattern portion, wherein the compensating pattern portion is adjacent to the main pattern potion;

providing a laser beam to scan a predetermined region of the amorphous silicon film through the main pattern portion to transform the amorphous silicon film into a polysilicon film; and

irradiating the laser beam to the predetermined region of the polysilicon film through the compensating pattern portion.

7 . The method of claim 6 , wherein the compensating pattern portion is transparent.

8 . The method of claim 6 , wherein the compensating pattern portion is translucent.

9 . The method of claim 6 , wherein the compensating pattern portion comprises a dummy pattern.

10 . The method of claim 6 , wherein the laser beam is a semi-Gaussuan beam.

11 . The method of claim 6 , wherein the laser beam is a flat-top shaped beam.

12 . The method of claim 6 , wherein the intensity of the laser beam is 600 mJ/cm 2 .

13 . The method of claim 6 , wherein the energy ratio of the laser beam through the compensating pattern portion to that through the main pattern portion is ⅓ to ⅗.

14 . The method of claim 6 , wherein the intensity of the laser beam is below a full melt threshold intensity: 370 mJ/cm 2 of the polysilicon film.

15 . A method for improving polysilicon film crystallinity in a sequential lateral solidification (SLS) process, comprising:

providing an amorphous silicon film;

providing a mask;

using the mask in a sequential lateral solidification process to transform the amorphous silicon film into a polysilicon film; and

fully annealing the polysilicon film.

16 . The method of claim 15 , wherein the step for fully annealing the polysilicon film utilizes an excimer laser annealing process.

17 . The method of claim 15 , wherein a scanning speed of the mask through the amorphous silicon film is 0.6 cm/sec and the energy of the laser beam used in the scanning is 370 mJ/cm 2 .

18 . The method of claim 15 , the method for fully annealing further comprising steps of:

providing a compensating mask; and

irradiating a laser beam through the compensating mask to the polysilicon film.