Abstract: 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-? 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-? 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.

Abstract: A deflecting mirror which deflects a laser beam emitted from a laser oscillator, a transfer lens, a cylindrical lens array which divides the laser beam having passed through the transfer lens into a plurality of laser beams, and a condensing lens which superposes the laser beams formed in the cylindrical lens array are included. The following formula is satisfied: 1/f=1/(a+b)+1/c, when: “a” is a distance between an emission opening of the laser oscillator and the deflecting mirror; “b” is a distance between the deflecting mirror and the transfer lens; “c” is a distance between the transfer lens and an incidence plane of the cylindrical lens array; and “f” is a focal length of the transfer lens.

Abstract: The present invention provides an optical component for fixing a lens comprising a base, a holder, and a fastener. The base has a concave side surface and at least one first hole. The holder has a cylindrical shape and has a second hole penetrating through a center portion of at least one of the top surface and the bottom surface thereof. The lens is sandwiched between the holder and the part of the base which extends from the edge of the side surface to the inner side and which corresponds to the inner part of a circle drawn so as to circumscribe all the insertion holes. The base and the holder are fastened by the fasteners inserted in the first insertion hole and the second insertion hole.

Abstract: It is an object to achieve continuous crystal growth without optical interference using a compact laser irradiation apparatus. A megahertz laser beam is split and combined to crystallize a semiconductor film. At this point of time, an optical path difference is provided between the split beams to reduce optical interference. The optical path difference is set to have a length equivalent to the pulse width of the megahertz laser beam or more and less than a length equivalent to the pulse repetition interval; thus, optical interference can be suppressed with a very short optical path difference. Therefore, laser beams can be applied continuously and efficiently without energy deterioration.

Abstract: The present invention is to provide a beam homogenizer, a laser irradiation apparatus, and a method for manufacturing a semiconductor device, which can suppress the loss of a laser beam and form a beam spot having homogeneous energy distribution constantly on an irradiation surface without being affected by beam parameters of a laser beam. A deflector is provided at an entrance of an optical waveguide or a light pipe used for homogenizing a laser beam emitted from a laser oscillator. A pair of reflection planes of the deflector is provided so as to have a tilt angle to an optical axis of the laser beam, whereby the entrance of the optical waveguide or the light pipe is expanded. Accordingly, the loss of the laser beam can be suppressed. Moreover, by providing an angle adjusting mechanism to the deflector, a beam spot having homogeneous energy distribution can be formed at an exit of the optical waveguide.

Abstract: The present invention is to provide a laser irradiation technique for irradiating the irradiation surface with the laser beam having homogeneous intensity distribution using a cylindrical lens array without being affected by the intensity distribution of the original beam. A laser beam emitted from a laser oscillator is divided by two kinds of cylindrical lens arrays into a plurality of beams, which are two kinds of linear laser beams with their energy intensity distribution inverted each other, and the two kinds of linear laser beams are superposed in a minor-axis direction. This can form the linear laser beam having homogeneous intensity distribution on the irradiation surface.

Abstract: Since the arrangement of the optical elements in the optical system is limited because of their characteristic, designing the optical system for forming the desired laser beam is difficult. An object of the present invention is to design the optical system having the desired function without being affected by the limit in the arrangement of the optical elements. Consequently, an off-axis cylindrical lens array is used as a cylindrical lens array acting on a long-side direction of the beam.

Abstract: It is an object of the present invention to provide a laser irradiation apparatus and an optical component used therein which can prevent the interference between the incident light and the reflected light from the rear surface of the substrate to be processed and which can suppress the damage of the optical component due to the reflected light.

Abstract: The present invention provides the laser irradiation apparatus that has a galvanometer mirror and an f-&thgr; lens optical system, can offset the change of the energy due to the transmittance change of the f-&thgr; lens, and can scan a laser beam while the change of the energy on a substrate is suppressed. Further, the laser beam energy that is incident on the lens is controlled in advance by combining the optical system changing the branching ratio of polarization of the laser beam and the optical system having dependence on direction of polarization of the laser beam and changed continuously according to the transmittance of the lens on which the laser beam is incident. The laser energy is controlled to offset the transmittance of the lens, and thereby energy fluctuation of the laser beam irradiation of a substrate can be prevented.