Abstract: In a light-emitting diode, which comprises epitaxial wafer where a gallium phosphide or a gallium phosphide arsenide mixed crystal epitaxial layer is grown on a III-V family compound single crystal substrate having zinc blende type crystal structure, the surface of said substrate has a plane tilted by 5 to 16.degree. from a (100) plane toward ?010!, ?001!, ?0-10! or ?00-1!, or a plane having crystallographically equivalent crystal plane orientation to this plane. As a result, it is possible to improve light emitting output and to ensure longer service life.

Abstract: The present invention relates to an epitaxial wafer including a PN junction, which is improved in terms of light output and can have a good-enough ohmic electrode formed thereon. Epitaxial layers are formed of GaAs.sub.1-x P.sub.x where 0.45 <.times..ltoreq.1). A first P-type layer is formed by a vapor-phase growth process, and a second P-type layer is formed on the first P-type layer by a thermal diffusion process, said second P-type layer having a carrier concentration higher than that of said first P-type layer.

Abstract: There is provided a method for suppressing generation of cracks or damages on a compound semiconductor epitaxial wafer during an epitaxial growth due to growth of an epitaxial layer on the rear surface at the edge of the epitaxial layer which is located at the upstream side of the flow of the source gas. In manufacturing a semiconductor wafer by growing a single crystal semiconductor epitaxial layer having a zinc blend structure on a single crystal semiconductor substrate having a zinc blend structure, the surface of the single crystal semiconductor substrate has (100) surface orientation having an off angle and a source gas is supplied in the direction of the off angle or in a direction at 30.degree. or less to the direction at 180.degree. thereto.