Abstract: A semiconductive GaAs wafer has a diameter of 4 inches or more, and an in-wafer plane dislocation density of 30,000/cm2 or more and 100,000/cm2 or less. A semiconductive GaAs wafer is made by growing a GaAs single crystal under a temperature gradient of 20° C./cm or more and 150° C./cm or less formed in the crystal so that the semiconductive GaAs wafer has an in-wafer plane dislocation density of 30,000/cm2 or more and 100,000/cm2 or less.

Abstract: A crystal growth furnace for a compound semiconductor single crystal has: a small diameter section for placing a seed crystal therein; an increasing diameter section that has diameters to increase from the small diameter section to upward; and a constant diameter section that extends from the increasing diameter section to upward. The increasing diameter section has an angle of 120 degrees or more and less than 160 degrees between inner walls opposed to each other.

Abstract: A Si-doped gallium arsenide single crystal substrate has a carrier concentration of 0.1×1018 to 5.0×1018/cm3. The substrate is made by Vertical Bridgeman (VB) method or Vertical Gradient Freeze (VGF) method, and a minimum value and a maximum value of the carrier concentration in substrate plane are within a dispersion of 10% or less of an average carrier concentration in substrate plane.

Abstract: A vessel 1 composed of pyrolitic boron nitride (PBN) for growing a compound semiconductor single crystal is provided with a seed crystal accommodating part 1a, a crystal growth part 1b, and a diameter increasing part 1c, wherein the vessel 1 is composed of pyrolitic boron plate (PBN) and a value of X-ray diffraction integrated intensity ratio {I(002)/I(100)} of (002) plane to (100) plane, measured at a plane vertical to a thickness direction of the PBN plate is more than 50 across a whole region of the vessel 1. In the vertical crystal growth process, a high quality compound semiconductor single crystal with less crystal defect such as dislocation can be obtained by using the vessel 1 for growing a compound semiconductor single crystal and a method for fabricating a compound semiconductor single crystal using the vessel 1, which can be easily fabricated and by which a shape of melt/crystal interface can be controlled without using complicated equipments.

Abstract: A semiconductive GaAs wafer has a diameter of 4 inches or more, and an in-wafer plane dislocation density of 30,000/cm2 or more and 100,000/cm2 or less. A semiconductive GaAs wafer is made by growing a GaAs single crystal under a temperature gradient of 20° C./cm or more and 150° C./cm or less formed in the crystal so that the semiconductive GaAs wafer has an in-wafer plane dislocation density of 30,000/cm2 or more and 100,000/cm2 or less.

Abstract: A Si-doped gallium arsenide single crystal substrate has a carrier concentration of 0.1×1018 to 5.0×1018/cm3. The substrate is made by Vertical Bridgeman (VB) method or Vertical Gradient Freeze (VGF) method, and a minimum value and a maximum value of the carrier concentration in substrate plane are within a dispersion of 10% or less of an average carrier concentration in substrate plane.

Abstract: A crystal growth furnace for a compound semiconductor single crystal has: a small diameter section for placing a seed crystal therein; an increasing diameter section that has diameters to increase from the small diameter section to upward; and a constant diameter section that extends from the increasing diameter section to upward. The increasing diameter section has an angle of 120 degrees or more and less than 160 degrees between inner walls opposed to each other.

Abstract: This invention relates to fabrication of a single crystal of a compound semiconductor according to the vertical Bridgman method which improves a recess in the interface between solid and melt and can obtain a stable yield of single crystal growth characterized in that a part for discharging the heat of a crucible to the outside in the radial direction is formed at least in a part in the circumferential direction of a heater part for controlling the interface between solid and melt in a heater which surrounds the crucible and a semiconductor melt is gradually solidified from a lower part to an upper part in the crucible while maintaining the interface between solid and melt in a saddle shape, thereby growing a single crystal.

Abstract: This invention relates to fabrication of a single crystal of a compound semiconductor according to the vertical Bridgman method which improves a recess in the interface between solid and melt and can obtain a stable yield of single crystal growth characterized in that a part for discharging the heat of a crucible to the outside in the radial direction is formed at least in a part in the circumferential direction of a heater part for controlling the interface between solid and melt in a heater which surrounds the crucible and a semiconductor melt is gradually solidified from a lower part to an upper part in the crucible while maintaining the interface between solid and melt in a saddle shape, thereby growing a single crystal.

Abstract: This invention relates to fabrication of a single crystal of a compound semiconductor according to the vertical Bridgman method which improves a recess in the interface between solid and melt and can obtain a stable yield of single crystal growth characterized in that a part for discharging the heat of a crucible to the outside in the radial direction is formed at least in a part in the circumferential direction of a heater part for controlling the interface between solid and melt in a heater which surrounds the crucible and a semiconductor melt is gradually solidified from a lower part to an upper part in the crucible while maintaining the interface between solid and melt in a saddle shape, thereby growing a single crystal.