Laser irradiation method, laser irradiation apparatus, and method for manufacturing semiconductor device

A laser irradiation method comprising:

• emitting a first laser beam from a first laser oscillator;
• emitting a second laser beam from a second laser oscillator;
• emitting a third laser beam from a third laser oscillator;
• combining the first laser beam with the second laser beam by a first dichroic mirror, thereby forming a first combined laser beam;
• combining a first combined laser beam with a third laser beam by a second dichroic mirror, thereby forming a second combined laser beam;
• and
• projecting the second laser beam to an irradiation surface,
• wherein the first laser beam passes through the first dichroic mirror and the second laser beam is reflected on the first dichroic mirror,
• wherein the first combined laser beam passes through the second dichroic mirror and the third laser beam is reflected on the second dichroic mirror, and
• wherein each wavelength of the first, second, and third laser beams is different.

A laser irradiation method comprising:

• emitting a first laser beam from a first laser oscillator;
• emitting a second laser beam from a second laser oscillator;
• emitting a third laser beam from a third laser oscillator;
• emitting a fourth laser beam from a fourth laser oscillator;
• combining the first laser beam with the second laser beam by a first dichroic mirror, thereby forming a first combined laser beam;
• combining the third laser beam with the fourth laser beam by a second dichroic mirror, thereby forming a second combined laser beam;
• combining the first combined laser beam with the second combined laser beam by a polarizer, thereby forming a third combined laser beam;
• and
• projecting the third combined laser beam to an irradiation surface,
• wherein the first laser beam passes through the first dichroic mirror and the second laser beam is reflected on the first dichroic mirror,
• wherein the third laser beam passes through the second dichroic mirror and the fourth laser beam is reflected on the second dichroic mirror,
• wherein the first combined laser beam passes through the polarizer and the second combined laser beam is reflected on the polarizer, and
• wherein wavelength of the first laser beam is different from that of the second laser beam, and
• wherein wavelength of the third laser beam is different from that of the fourth laser beam.

A laser irradiation method comprising:

• emitting a first laser beam from a first laser oscillator;
• emitting a second laser beam from a second laser oscillator;
• emitting a third laser beam from a third laser oscillator;
• emitting a fourth laser beam from a fourth laser oscillator;
• emitting a fifth laser beam from a fifth laser oscillator;
• emitting a sixth laser beam from a sixth laser oscillator;
• combining the first laser beam emitted with a second laser beam by a first dichroic mirror, thereby forming a first combined laser beam, wherein the first laser beam passes through the first dichroic mirror and the second laser beam is reflected on the first dichroic mirror;
• combining a first combined laser beam with the third laser beam by a second dichroic mirror, thereby forming a second combined laser beam, wherein the first combined laser beam passes through the second dichroic mirror and the third laser beam is reflected on the second dichroic mirror;
• combining the fourth laser beam emitted with the fifth laser beam by a third dichroic mirror, thereby forming a third combined laser beam, wherein the fourth laser beam passes through the third dichroic mirror and the fifth laser beam is reflected on the third dichroic mirror;
• combining the third combined laser beam with the sixth laser beam by a fourth dichroic mirror, thereby forming a fourth combined laser beam, wherein the third combined laser beam passes through the fourth dichroic mirror and the sixth laser beam is reflected on the fourth dichroic mirror;
• combining the second combined laser beam with the fourth combined laser beam by a polarizer, thereby forming a fifth combined laser beam, wherein the second combined laser beam passes through the polarizer and the fourth combined laser beam is reflected on the polarizer;
• and
• projecting the fifth combined laser beam to an irradiation surface,
• wherein wavelengths of the first, second third laser beams are different from each other, and
• wherein wavelengths of the fourth, fifth, and sixth laser beams are different from each other.

A manufacturing method for a semiconductor device comprising:

• emitting a first laser beam from a first laser oscillator;
• emitting a second laser beam from a second laser oscillator;
• combining the first laser beam with the second laser beam by a dichroic mirror;
• crystallizing a semiconductor film by irradiating the semiconductor film with the combined laser beam,
• wherein the first laser beam passes through the first dichroic mirror and the second laser beam is reflected on the first dichroic mirror, and
• wherein wavelength of the first laser beam is different from that of the second laser beam.

A manufacturing method for a semiconductor device comprising:

• emitting a first laser beam from a first laser oscillator;
• emitting a second laser beam from a second laser oscillator;
• emitting a third laser beam from a third laser oscillator;
• combining the first laser beam with the second laser beam by a first dichroic mirror, thereby forming a first combined laser beam;
• combining a first combined laser beam a third laser beam by a second dichroic mirror, thereby forming a second combined laser beam;
• and
• crystallizing a semiconductor film by irradiating the semiconductor film with the second combined laser,
• wherein the first laser beam passes through the first dichroic mirror and the second laser beam is reflected on the first dichroic mirror,
• wherein the first combined laser beam passes through the second dichroic mirror and the third laser beam is reflected on the second dichroic mirror, and
• wherein wavelengths of the first, second, third laser beams are different from each other.

A laser irradiation apparatus comprising:

• a first laser oscillator emitting a first laser beam;
• a second laser oscillator emitting a second laser beam having a different wavelength from the first laser beam;
• a dichroic mirror for combining the first and second laser beams by transmitting the first laser beam and reflecting the second laser beam;
• and
• a stage.

A laser irradiation apparatus comprising:

• a first laser oscillator emitting a first laser beam;
• a second laser oscillator emitting a second laser beam having a different wavelength from the first laser beam;
• a first dichroic mirror for combining the first and second laser beams into a first combined laser beam by transmitting the first laser beam and reflecting the second laser beam;
• a third laser oscillator emitting a third laser beam having a different wavelength from the first and second laser beams;
• a second dichroic mirror for combining the third laser beam and the first combined laser beam into a second combined laser beam by transmitting the first combined laser beam and reflecting the third laser beam;
• and
• a stage.

A laser irradiation apparatus comprising:

• a first laser oscillator emitting a first laser beam;
• a second laser oscillator emitting a second laser beam having a different wavelength from the first laser beam;
• a first dichroic mirror for combining the first and second laser beams into a first combined laser beam by transmitting the first laser beam and reflecting the second laser beam;
• a half-wave plate for transmitting the first combined laser beam;
• a third laser oscillator emitting a third laser beam;
• a fourth laser oscillator emitting a fourth laser beam having a different wavelength from the third laser beam;
• a second dichroic mirror for combining the third and fourth laser beams into a second combined laser beam by transmitting the third laser beam and reflecting the fourth laser beam;
• a polarizer for combining the first and second combined laser beams into a third combined laser beam by transmitting the first combined laser beam and reflecting the second combined laser beam;
• and
• a stage.

A laser irradiation apparatus comprising:

• a first laser oscillator emitting a first laser beam;
• a second laser oscillator emitting a second laser beam having a different wavelength from the first laser beam;
• a first dichroic mirror for combining the first and second laser beams into a first combined laser beam by transmitting the first laser beam and reflecting the second laser beam;
• a third laser oscillator emitting a third laser beam having a different wavelength from the first and second laser beams;
• a second dichroic mirror for combining the first combined laser beam and the third laser beam into a second combined laser beam by transmitting the first combined laser beam and reflecting the third laser beam;
• a half-wave plate for transmitting the second combined laser beam;
• a fourth laser oscillator emitting a fourth laser beam;
• a fifth laser oscillator emitting a fifth laser beam having a different wavelength from the fourth laser beam;
• a third dichroic mirror for combining the fourth and fifth laser beams into a third combined laser beam by transmitting the fourth laser beam and reflecting the fifth laser beam;
• a sixth laser oscillator emitting a sixth laser beam having a different wavelength from the fourth and fifth laser beams;
• a fourth dichroic mirror for combining the third combined laser beam and the sixth laser beam into a fourth combined laser beam by transmitting the third combined laser beam and reflecting the sixth laser beam;
• a polarizer for combining the second combined laser beam and the fourth combined laser beam into a fifth combined laser beam by transmitting the second combined laser beam and reflecting the fourth combined laser beam;
• and
• a stage.