Method of processing beam, laser irradiation apparatus, and method of manufacturing semiconductor device

A method of processing a laser beam, the method comprising:

• oscillating a laser beam;
• dividing the laser beam into two laser beams in a first direction, the two laser beams having polarization directions perpendicular to each other;
• dividing the two laser beams into a plurality of laser beams in a second direction perpendicular to the first direction, the plurality of laser beams having optical path lengths different from each other;
• and
• combining the plurality of laser beams into one laser beam on or in the vicinity of the irradiation plane.

A method of processing a linear laser beam, the method comprising:

• an oscillating a laser beam;
• dividing the linear laser beam into two laser beams in a first direction, the two laser beams having polarization directions perpendicular to each other;
• dividing the two laser beams into a plurality of laser beams in a second direction perpendicular to the first direction, the plurality of laser beams having optical path lengths different from each other;
• and
• combining the plurality of laser beams into one laser beam on or in the vicinity of the irradiation plane to make the distribution of energy of the one linear laser beam uniform in a long-dimension direction.

A method of processing a laser beam, the method comprising:

• oscillating a laser beam;
• dividing the laser beam into two laser beams in a first direction, the two laser beams having circular polarization directions independent of each other;
• dividing the two laser beams into a plurality of laser beams in a second direction perpendicular to the first direction, the plurality of laser beams having optical path lengths different from each other;
• and
• combining the plurality of laser beams into one laser beam on or in the vicinity of the irradiation plane.

A method of processing a linear laser beam, the method comprising:

• oscillating a laser beam:
• dividing the laser beam into two laser beams in a first direction, the two laser beam having circular polarization directions independent of each other;
• dividing the two laser beams into a plurality of laser beams in a second direction perpendicular to the first direction, the plurality of laser beams having optical path lengths different from each other;
• and
• combining the plurality of laser beams into one linear laser beam on or in the vicinity of the irradiation plane to make the distribution of energy of the one linear laser beam uniform in a long-dimension direction.

A laser irradiation apparatus comprising:

• a laser oscillator for forming a laser beam having coherence;
• means for dividing the laser beam into two laser beams in a first direction, the divided two laser beams having polarization directions independent of each other;
• means for dividing the two laser beams into a plurality of laser beams in a second direction perpendicular to the first direction, the plurality of laser beams having optical path lengths different from each other;
• and
• means for combining the plurality of laser beams into one laser beam on or in the vicinity of the irradiation plane.

A laser irradiation apparatus comprising:

• a laser oscillator for forming a laser beam of linearly polarized laser light having coherence;
• means for dividing the laser beam into two laser beams in a first direction, the two laser beams having polarization directions perpendicular to each other;
• means for dividing the two laser beams into a plurality of laser beams in a second direction perpendicular to the first direction, the plurality of laser beams having optical path lengths different from each other;
• and
• means for combining the plurality of laser beams into one laser beam on or in the vicinity of the irradiation plane.

A laser irradiation apparatus for forming a linear laser beam distributed along or in the vicinity of an irradiation plane, said apparatus comprising:

• a laser oscillator for forming a laser beam of linearly polarized laser light having coherence;
• means for dividing the laser beam into two laser beams in a first direction, the two laser beams having polarization directions perpendicular to each other;
• means for dividing the two laser beams into a plurality of laser beams in a second direction perpendicular to the first direction, the plurality of laser beams having optical path lengths different from each other;
• means for combining the plurality of laser beams into one linear laser beam on or in the vicinity of the irradiation plane to make the distribution of energy of the linear laser beam uniform in a short-dimension direction;
• and
• means for combining the plurality of laser beams into the one linear laser beam on or in the vicinity of the irradiation plane to make the distribution of energy of the one linear laser beam uniform in a long-dimension direction.

A laser irradiation apparatus comprising:

• a laser oscillator for forming a laser beam of circularly polarized laser light having coherence;
• means for dividing the laser beam into two laser beams in a first direction, the two laser beams having circular polarization directions independent of each other;
• means for dividing the two laser beams into a plurality of laser beams in a second direction perpendicular to the first direction, the plurality of laser beams having optical path lengths different from each other;
• and
• means for combining the plurality of laser beams into one laser beam on or in the vicinity of the irradiation plane.

A laser irradiation apparatus for forming a linear laser beam distributed along or in the vicinity of an irradiation plane, said apparatus comprising:

• a laser oscillator for forming a laser beam of circularly polarized laser light having coherence;
• means for dividing the laser beam into two laser beams in a first direction, the two laser beams having circular polarization directions independent of each other;
• means for dividing the laser beam into a plurality of laser beams in a second direction perpendicular to the first direction, the plurality of laser beams having optical path lengths different from each other;
• and
• means for combining the plurality of laser beams into one linear laser beam on or in the vicinity of the irradiation plane to make the distribution of energy of the one linear laser beam uniform in a long-dimension direction.

A method of manufacturing a semiconductor device, the method comprising:

• forming a semiconductor film over a substrate;
• and
• irradiating a linear laser beam to said semiconductor film;
• wherein the step of irradiating the linear laser beam includes forming the linear laser beam by:
• oscillating a laser beam having coherence;
• dividing the laser beam into two laser beams in a first direction, the divided two laser beams having polarization directions independent of each other;
• dividing the two laser beam into a plurality of laser beams in a second direction perpendicular to the first direction;
• and
• combining the plurality of laser beams into the linear laser beam on or in the vicinity of the irradiation plane such that the linear laser beam has a long-dimension direction parallel to the second direction.