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 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.