There are provided a laser irradiation apparatus, a laser irradiation method, and a semiconductor device manufacturing method that reduce irradiation unevenness of a laser beam.

A laser irradiation apparatus includes a waveform shaping device (20). The waveform shaping device (20) includes a laser beam source (11), a first waveform shaping unit (30) that shapes the pulse waveform of a pulse laser beam by applying a delay according to an optical path length difference between two light beams (L11 and L12) branched by a first beam splitter (31), a wave plate that changes the polarization state of the pulse laser beam from the first waveform shaping unit (30), and a second waveform shaping unit (40) that shapes the pulse waveform of the pulse laser beam by applying a delay according to an optical path length difference between two light beams (L15 and L16) branched by a second beam splitter (41).

A laser irradiation apparatus including: a laser light source configured to emit a linearly polarized pulsed laser light; a first half-wave plate rotatably provided in an optical path of the pulsed laser light; a first polarization beam splitter configured to branch the pulsed laser light from the first half-wave plate into a first pulsed light and a second pulsed light; a second polarization beam splitter configured to combined the first pulsed light with the second pulsed light, the second pulsed light, the second pulsed light being delayed from the first pulsed light by using an optical path length difference between the first pulsed light and the second pulsed light; and a first wave plate rotatably provided in an optical path of a combined pulsed light generated by combining the first pulsed light with the second pulsed light at the second polarization beam splitter.

A laser crystallization apparatus includes light sources that emit a first laser beam and a second laser beam; a first beam homogenizer through which the first laser beam passes; a second beam homogenizer through which the second laser beam passes; and an optical array on which the first laser beam passed through the first beam homogenizer and the second laser beam passed through the second beam homogenizer are incident. A first path of the first laser beam passed through the first beam homogenizer and a second path of the second laser beam passed through the second beam homogenizer are different from each other. The first beam homogenizer includes first lenses having a first pitch. The second beam homogenizer includes second lenses having a second pitch. The first pitch of the first lenses and the second pitch of the second lenses are same each other.

A method for manufacturing a semiconductor crystalline thin film according to a viewpoint of the present disclosure includes radiating first pulsed laser light having a first pulse duration to an amorphous semiconductor to poly-crystallize the amorphous semiconductor and radiating second pulsed laser light having a second pulse duration shorter than the first pulse duration to an area of a semiconductor crystal having undergone the poly-crystallization to lower the height of ridges of the semiconductor crystal.

A laser irradiation method includes a first scanning wherein a laser beam is scanned in a first region having a width in the X direction and a length in the Y direction by moving a laser irradiation area on the surface of the substrate along the Y direction using a spot laser beam, and a second scanning wherein laser beam is scanned in a second region having a width in the X direction and a length in the Y direction by moving a laser irradiation area on the surface of the substrate along the Y direction using the spot laser beam. A center of the second region is spaced apart from a center of the first region in the X direction.

A first laser irradiation, in which an amorphous silicon film is irradiated with a first laser beam for transformation of the amorphous silicon film to a microcrystalline silicon film, and a second laser irradiation, in which a second laser beam moves along a unidirectional direction with the microcrystalline silicon film as a starting point for lateral crystal growth of growing crystals constituting a crystallized silicon film, are carried out to form a microcrystalline silicon film and a crystallized silicon film alternately along the unidirectional direction.

A thin film transistor 101 includes: a gate electrode 2; a gate insulating layer 3; a semiconductor layer 4 including an amorphous semiconductor layer 4a and a crystalline semiconductor layer 4c that is disposed on a portion of the amorphous semiconductor layer 4a, the semiconductor layer 4 including an active region Rc that includes the crystalline semiconductor layer 4c and a portion of the amorphous semiconductor layer 4a, and the semiconductor layer 4 including first and second semiconductor regions Rs and Rd which respectively include first and second amorphous portions A1 and A2 that are located on opposite sides of the active region Rc; a protective insulating layer 5; first and second contact layers Cs and Cd disposed on the semiconductor layer 4 and the protective insulating layer 5; a source electrode 8s; and a drain electrode 8d. The first contact layer Cs includes a first amorphous contact layer 7s that is directly in contact with the first semiconductor region Rs and a portion of a side surface of the crystalline semiconductor layer 4c. The second contact layer Cd includes a second amorphous contact layer 7d that is directly in contact with the second semiconductor region Rd and another portion of the side surface of the crystalline semiconductor layer 4c.

A laser crystallization apparatus includes a plurality of laser generators which generate a plurality of laser beams, a plurality of attenuators which adjust energy intensity of the plurality of laser generators, and an optical module which overlap outputs of the plurality of attenuators to output a line beam. A first attenuator of the plurality of attenuators attenuates the energy intensity of the corresponding laser beam, and a second attenuator of the plurality of attenuators maintains the energy intensity of the corresponding laser beam.

A laser annealing apparatus includes a plurality of lasers, a laser controller that controls the plurality of lasers such that a plurality of laser beams generated from the plurality of lasers is emitted at different timings, beam mixer optics that outputs a processing beam by mixing the plurality of laser beams of which output timings are adjusted, and focus optics that outputs the processing beam of which focus is adjusted. The processing beam includes a first processing laser beam having a first pulse, a second processing laser beam having a second pulse following the first pulse, and a third processing laser beam having a third pulse following the second pulse. A first peak of the first pulse is smaller than a second peak of the second pulse, and a third peak of the third pulse is smaller than the second peak.

Methods for thermal treatment on a semiconductor device is disclosed. One method includes obtaining a pattern of a treatment area having amorphous silicon, aligning a laser beam with the treatment area, the laser beam in a focused laser spot having a spot area equal to or greater than the treatment area, and performing a laser anneal on the treatment area by emitting the laser beam towards the treatment area for a treatment period.