Gallium arsenide single crystal substrate and method of producing same

A gallium arsenide single crystal substrate comprising a main surface having a circular shape, wherein

• the gallium arsenide single crystal substrate has a first integrated intensity ratio, a second integrated intensity ratio, a third integrated intensity ratio, a fourth integrated intensity ratio, and a fifth integrated intensity ratio,
• each of the first integrated intensity ratio and the third integrated intensity ratio is obtained by determining each of spectra of detection intensities of 3d electrons of gallium and arsenic with respect to binding energy of a photoelectron emitted to outside of the gallium arsenide single crystal substrate based on X-ray photoelectron spectroscopy in which X-ray is applied to a center of the main surface under conditions of an X-ray incident energy of 600 eV and a photoelectron take-off angle of 30°, each of the second integrated intensity ratio and the fifth integrated intensity ratio is obtained by determining each of spectra of detection intensities of 3d electrons of the gallium and the arsenic with respect to binding energy of a photoelectron emitted to the outside of the gallium arsenide single crystal substrate based on X-ray photoelectron spectroscopy in which X-ray is applied to the center of the main surface under conditions of an X-ray incident energy of 600 eV and a photoelectron take-off angle of 85°,
• the fourth integrated intensity ratio is obtained by determining each of spectra of detection intensities of 3d electrons of the gallium and the arsenic with respect to binding energy of a photoelectron emitted to the outside of the gallium arsenide single crystal substrate based on X-ray photoelectron spectroscopy in which X-ray is applied to the center of the main surface under conditions of an X-ray incident energy of 600 eV and a photoelectron take-off angle of 45°,
• each of the first integrated intensity ratio and the second integrated intensity ratio is a ratio of a sum of an integrated intensity of an arsenic element present as diarsenic pentoxide, an integrated intensity of an arsenic element present as diarsenic trioxide, an integrated intensity of an arsenic element present as gallium arsenide, and an integrated intensity of an arsenic element present as a metal arsenic to a sum of an integrated intensity of a gallium element present as digallium monoxide, an integrated intensity of a gallium element present as digallium trioxide, and an integrated intensity of a gallium element present as the gallium arsenide,
• each of the third integrated intensity ratio, the fourth integrated intensity ratio, and the fifth integrated intensity ratio is a ratio of a sum of an integrated intensity of the arsenic element present as the diarsenic pentoxide and an integrated intensity of the arsenic element present as the diarsenic trioxide to a sum of an integrated intensity of the gallium element present as the digallium monoxide and an integrated intensity of the gallium element present as the digallium trioxide,
• the second integrated intensity ratio is 0.9 or more and 1.05 or less,
• each of the third integrated intensity ratio and the fourth integrated intensity ratio is 1.0 or less,
• the fifth integrated intensity ratio is 0.8 or less, and
• a ratio of the first integrated intensity ratio to the second integrated intensity ratio is 0.5 or more and 1 or less.