Laser annealing apparatus
View Patent ↗A laser annealing apparatus used in a crystallization process of an amorphous silicon thin film. The laser annealing apparatus includes a laser beam generation unit generating a laser beam, an optical system dividing the laser beam into a plurality of linear laser beams and including a focusing lens focusing the linear laser beams and projecting the focused linear laser beam on a substrate to be processed, and a focusing lens adjustment device adjusting a perpendicular distance and a rotation angle of the focusing lens relative to the substrate.
1. A laser annealing apparatus, comprising:
a laser beam generation unit generating a laser beam providing annealing of an amorphous silicon thin film;
an optical system dividing the laser beam into a plurality of linear laser beams and comprising a focusing lens focusing the divided linear laser beams to form a focused linear laser beam, and projecting the focused linear laser beam onto a substrate; and
a focusing lens adjustment device comprising a worm gear comprising a pair of worms and a pair of worm wheels, which are symmetrically disposed near both sides of the focusing lens relative to a vertical line passing through a center of the focusing lens, and adjusting a perpendicular distance and a rotation angle of the focusing lens with respect to the substrate via the worm gear.
2. The laser annealing apparatus of claim 1 , wherein the laser beam is an excimer laser beam.
3. The laser annealing apparatus of claim 1 , wherein the laser beam generated by the laser beam generation unit is a rectangular laser beam.
4. The laser annealing apparatus of claim 1 , wherein the optical system further comprises a beam homogenizer dividing the laser beam generated by the laser beam generation unit into the plurality of linear laser beams and homogenizing the linear laser beams.
5. The laser annealing apparatus of claim 1 , wherein the optical system further comprises a reflector changing a path of the laser beam generated by the laser beam generation unit in a direction perpendicular to the original path of the laser beam.
6. The laser annealing apparatus of claim 5 , wherein the reflector is a mirror.
7. The laser annealing apparatus of claim 6 , wherein the focusing lens is disposed between the reflector and the substrate.
8. The laser annealing apparatus of claim 1 , wherein the focusing lens is a cylindrical lens.
9. The laser annealing apparatus of claim 1 , wherein the worms are separately connected to driving motors that are symmetrically disposed on both radially opposite sides of the focusing lens relative to the vertical line passing through the center of the focusing lens;
wherein the worm wheels are symmetrically disposed relative to the vertical line passing through the center of the focusing lens and respectively connect to both sides of the focusing lens; and
wherein driving force of each driving motor is transferred to the corresponding sides of the focusing lens.
10. The laser annealing apparatus of claim 9 , wherein the perpendicular distance of the focusing lens relative to the substrate is adjusted by controlling a voltage applied to each driving motor.
11. The laser annealing apparatus of claim 9 , wherein the rotation angle of the focusing lens relative to the substrate is adjusted by controlling a voltage applied to each driving motor.
12. The laser annealing apparatus of claim 1 , further comprising a stage on which the substrate is mounted and which moves the substrate.
13. The laser annealing apparatus of claim 12 , wherein the stage moves in a direction perpendicular to the lengthwise direction of the linear laser beam.