Abstract: An indium phosphide crystal substrate has a diameter of 100-205 mm and a thickness of 300-800 ?m and includes any of a flat portion and a notch portion. In any of a first flat region and a first notch region, when an atomic concentration of sulfur is from 2.0×1018 to 8.0×1018 cm?3, the indium phosphide crystal substrate has an average dislocation density of 10-500 cm?2, and when am atomic concentration of tin is from 1.0×1018 to 4.0×1018 cm?3 or an atomic concentration of iron is from 5.0×1015 to 1.0×1017 cm?3, the indium phosphide crystal substrate has an average dislocation density of 500-5000 cm?2.

Abstract: An indium phosphide crystal substrate has a diameter of 100-205 mm and a thickness of 300-800 ?m and includes any of a flat portion and a notch portion. In any of a first flat region and a first notch region, when an atomic concentration of sulfur is from 2.0×1018 to 8.0×1018 cm?3, the indium phosphide crystal substrate has an average dislocation density of 10-500 cm?2, and when an atomic concentration of tin is from 1.0×1015 to 4.0×1018 cm?3 or an atomic concentration of iron is from 5.0×1015 to 1.0×1017 cm?3, the indium phosphide crystal substrate has an average dislocation density of 500-5000 cm?2.

Abstract: A group III nitride semiconductor crystal substrate has a diameter of at least 25 mm and not more than 160 mm. The resistivity of the group III nitride semiconductor crystal substrate is at least 1×10?4 ?·cm and not more than 0.1 ?·cm. The resistivity distribution in the diameter direction of the group III nitride semiconductor crystal is at least ?30% and not more than 30%. The resistivity distribution in the thickness direction of the group III nitride semiconductor crystal is at least ?16% and not more than 16%.

Abstract: An optical wavelength conversion element includes a cesium-lithium-borate crystal processed into a 10-mm long optical element cut in an orientation that allows a fourth harmonic of a Nd:YAG laser to be generated. A transmittance (Ta) at 3589 cm?1 in an infrared transmission spectrum of the optical element is used as an index that indicates a content of water impurities in the crystal and is independent of a polarization direction. An actual measurement of the transmittance Ta is at least 1%, without taking into account loss at an optically polished surface of the crystal. A wavelength conversion device, a ultraviolet laser irradiation apparatus, a laser processing system, and a method of manufacturing an optical wavelength conversion element are also described.

Abstract: An AlxGayIn1-x-yN crystal substrate of the present invention has a main plane having an area of at least 10 cm2. The main plane has an outer region located within 5 mm from an outer periphery of the main plane, and an inner region corresponding to a region other than the outer region. The inner region has a total dislocation density of at least 1×102 cm?2 and at most 1×106 cm?2. It is thereby possible to provide an AlxGayIn1-x-yN crystal substrate having a large size and a suitable dislocation density for serving as a substrate for a semiconductor device, a semiconductor device including the AlxGayIn1-x-yN crystal substrate, and a method of manufacturing the same.

Abstract: A group III nitride semiconductor crystal substrate has a diameter of at least 25 mm and not more than 160 mm. The resistivity of the group III nitride semiconductor crystal substrate is at least 1×10?4 ?·cm and not more than 0.1 ?·cm. The resistivity distribution in the diameter direction of the group III nitride semiconductor crystal is at least ?30% and not more than 30%. The resistivity distribution in the thickness direction of the group III nitride semiconductor crystal is at least ?16% and not more than 16%.

Abstract: A borate-based crystal excellent in uniformity and reliability, which is useful as an optical wavelength conversion device, etc., and can be easily produced at low cost in a short period of time, by the steps of dissolving water-soluble starting materials in water to prepare an aqueous solution, evaporating water in the aqueous solution followed by sintering or evaporating the water and not sintering, thereby forming a crystal growth material, and melting the resultant material to grow a crystal. Further, a highly reliable laser oscillation apparatus can be achieved by using this crystal as an optical wavelength conversion device.

Abstract: An AlxGayIn1-x-yN crystal substrate of the present invention has a main plane having an area of at least 10 cm2. The main plane has an outer region located within 5 mm from an outer periphery of the main plane, and an inner region corresponding to a region other than the outer region. The inner region has a total dislocation density of at least 1×102 cm?2 and at most 1×106 cm-31 2. It is thereby possible to provide an AlxGayIn1-x-yN crystal substrate having a large size and a suitable dislocation density for serving as a substrate for a semiconductor device, a semiconductor device including the AlxGayIn1-x-yN crystal substrate, and a method of manufacturing the same.

Abstract: A growing method of a group III nitride semiconductor crystal includes the steps of preparing an underlying substrate, and growing a first group III nitride semiconductor crystal doped with silicon by using silicon tetrachloride (SiCl4) gas as doping gas, on the underlying substrate by vapor phase growth. The growth rate of the first group III nitride semiconductor crystal is at least 200 ?m/h and not more than 2000 ?m/h.

Abstract: A growing method of a group III nitride semiconductor crystal includes the steps of preparing an underlying substrate, and growing a group III nitride semiconductor crystal doped with silicon by using silicon tetrafluoride gas as doping gas, on the underlying substrate by vapor phase growth.

Abstract: A group III nitride semiconductor crystal substrate has a diameter of at least 25 mm and not more than 160 mm. The resistivity of the group III nitride semiconductor crystal substrate is at least 1×10?4 ?·m and not more than 0.1 ?·cm. The resistivity distribution in the diameter direction of the group III nitride semiconductor crystal is at least ?30% and not more than 30%. The resistivity distribution in the thickness direction of the group III nitride semiconductor crystal is at least ?16% and not more than 16%.

Abstract: An optical wavelength conversion element includes a cesium-lithium-borate crystal processed into a 10-mm long optical element cut in an orientation that allows a fourth harmonic of a Nd:YAG laser to be generated. A transmittance (Ta) at 3589 cm?1 in an infrared transmission spectrum of the optical element is used as an index that indicates a content of water impurities in the crystal and is independent of a polarization direction. An actual measurement of the transmittance Ta is at least 1%, without taking into account loss at an optically polished surface of the crystal. A wavelength conversion device, a ultraviolet laser irradiation apparatus, a laser processing system, and a method of manufacturing an optical wavelength conversion element are also described.

Abstract: A borate-based crystal excellent in uniformity and reliability, which is useful as an optical wavelength conversion device, etc., and can be easily produced at low cost in a short period of time, by the steps of dissolving water-soluble starting materials in water to prepare an aqueous solution, evaporating water in the aqueous solution followed by sintering or evaporating the water and not sintering, thereby forming a crystal growth material, and melting the resultant material to grow a crystal. Further, a highly reliable laser oscillation apparatus can be achieved by using this crystal as an optical wavelength conversion device.