Laser irradiation apparatus, laser irradiation method, and manufacturing method of semiconductor device
View Patent ↗To provide a laser irradiation apparatus and a laser irradiation method in which a region formed with microcrystals in a region irradiated with laser beams is decreased by disposing a slit in an optical system using a deflector, and laser processing can be favorably conducted to a semiconductor film. Further to provide a semiconductor manufacturing apparatus using the above-described laser irradiation apparatus and the laser irradiation method. In the optical system, an f-θ lens having an image space telecentric characteristic or a slit the shape of which is changed in accordance with the incidence angle of a laser beam, is used. The slit is disposed between the f-θ lens and an irradiation surface, and an image at a slit opening portion is projected onto the irradiation surface by a projection lens. By the above-described structure, laser irradiation can be uniformly conducted to a whole region scanned with laser beams.
1. A laser irradiation apparatus comprising:
a laser oscillator;
a deflector which deflects a laser beam emitted from the laser oscillator at a deflection surface;
an imaging optical system which condenses the laser beam deflected by the deflector to an irradiation surface;
a slit plate between the imaging optical system and the irradiation surface, wherein the slit plate intercepts an edge of the laser beam; and
a projection lens which projects an image formed at a slit opening portion of the slit plate in a path which the laser beam passes onto the irradiation surface,
wherein the deflector is capable of scanning the irradiation surface with the laser beam by changing an angle of inclination of the deflection surface,
wherein the slit opening portion is elongated in a direction parallel to a scanning direction of the laser beam.
2. The laser irradiation apparatus according to claim 1 , wherein the laser oscillator is at least one of a continuous-wave laser oscillator selected from the group consisting of an Ar laser, a Kr laser, a CO 2 laser, a YAG laser, a YVO 4 laser, a YLF laser, a YAIO 3 laser, a GdVO 4 laser, a Y 2 O 3 laser, a ruby laser, an alexandrite laser, a Ti:sapphire laser, a helium-cadmium laser, a GaN laser, a GaAs laser, and an InAs laser.
3. The laser irradiation apparatus according to claim 1 , wherein the laser oscillator is at least one of a pulsed laser oscillator selected from the group consisting of an Ar laser, a Kr laser, an excimer laser, a CO 2 laser, a YAG laser, a YVO 4 laser, a YLF laser, a YAIO 3 laser, a GdVO 4 laser, a Y 2 O 3 laser, a glass laser, a ruby laser, an alexandrite laser, a Ti:sapphire laser, a GaN laser, a GaAs laser, an InAs laser, a copper vapor laser, and a gold vapor laser.
4. The laser irradiation apparatus according to claim 1 , wherein the laser beam is a higher harmonic wave converted by a nonlinear optical device.
5. The laser irradiation apparatus according to claim 1 , wherein the deflector is at least one of the group consisting of a galvanometer mirror, a polygon mirror, an acousto-optic deflector, an electro optical deflector, a resonant scanner, a hologram scanner and a conical scanner.
6. The laser irradiation apparatus according to claim 1 , wherein the imaging optical system is an f-θ lens or a telecentric f-θ lens.
7. The laser irradiation apparatus according to claim 1 , wherein the projection lens is a convex cylindrical lens.
8. A laser irradiation apparatus comprising:
a laser oscillator;
an optical system which processes a laser beam emitted from the laser oscillator so as to form a linear beam spot on an irradiation surface;
a deflector which deflects the laser beam at a deflection surface;
an imaging optical system which condenses the laser beam deflected by the deflector to the irradiation surface;
a slit plate between the imaging optical system and the irradiation surface, wherein the slit plate intercepts an edge of the laser beam; and
a projection lens which projects an image formed at a slit opening portion of the slit plate in a path which the laser beam passes onto the irradiation surface,
wherein the deflector is capable of scanning the irradiation surface with the laser beam by changing an angle of inclination of the deflection surface, and
wherein the slit opening portion is elongated in a direction parallel to a scanning direction of the laser beam.
9. The laser irradiation apparatus according to claim 8 , wherein the laser oscillator is at least one of a continuous-wave laser oscillator selected from the group consisting of an Ar laser, a Kr laser, a CO 2 laser, a YAG laser, a YVO 4 laser, a YLF laser, a YAIO 3 laser, a GdVO 4 laser, a Y 2 O 3 laser, a ruby laser, an alexandrite laser, a Ti:sapphire laser, a helium-cadmium laser, a GaN laser, a GaAs laser, and an InAs laser.
10. The laser irradiation apparatus according to claim 8 , wherein the laser oscillator is at least one of a pulsed laser oscillator selected from the group consisting of an Ar laser, a Kr laser, an excimer laser, a CO 2 laser, a YAG laser, a YVO 4 laser, a YLF laser, a YAIO 3 laser, a GdVO 4 laser, a Y 2 O 3 laser, a glass laser, a ruby laser, an alexandrite laser, a Ti:sapphire laser, a GaN laser, a GaAs laser, an InAs laser, a copper vapor laser, and a gold vapor laser.
11. The laser irradiation apparatus according to claim 8 , wherein the laser beam is a higher harmonic wave converted by a nonlinear optical device.
12. The laser irradiation apparatus according to claim 8 , wherein the deflector is at least one of the group consisting of a galvanometer mirror, a polygon mirror, an acousto-optic deflector, an electro optical deflector, a resonant scanner, a hologram scanner and a conical scanner.
13. The laser irradiation apparatus according to claim 8 , wherein the imaging optical system is an f-θ lens or a telecentric f-θ lens.
14. The laser irradiation apparatus according to claim 8 , wherein the projection lens is a convex cylindrical lens.
15. The laser irradiation apparatus according to claim 8 , wherein the linear beam spot is scanned in a minor-axis direction.