GROUP III NITRIDE CRYSTAL SUBSTRATE, GROUP III NITRIDE CRYSTAL SUBSTRATE HAVING EPITAXIAL LAYER, AND SEMICONDUCTOR DEVICE AND METHOD FOR PRODUCING THE SAME

摘要

A group III nitride crystal substrate (1) is provided, wherein, a plane spacing of arbitrary specific parallel crystal lattice planes of the crystal substrate being obtained from X-ray diffraction measurement performed with variation of X-ray penetration depth from a main surface (1s) of the crystal substrate while X-ray diffraction conditions of the specific parallel crystal lattice planes of the group III nitride crystal substrate (1) are satisfied, a uniform distortion at a surface layer of the crystal substrate represented by a value of |d 1 - d 2 |/d 2 is equal to or lower than 1.7 × 10 -3 where d 1 indicates a plane spacing at the X-ray penetration depth of 0.3 µm and d 2 indicates a plane spacing at the X-ray penetration depth of 5 µm, and wherein a plane orientation of the main surface (1s) has an inclination angle equal to or greater than -10° and equal to or smaller than 10° in a [0001] direction with respect to a plane (1v) including a c axis (1c) of the crystal substrate. A group III nitride crystal substrate suitable for manufacturing a light emitting device with a blue shift of an emission suppressed, an epilayer-containing group III nitride crystal substrate, a semiconductor device and a method of manufacturing the same can thereby be provided.