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

摘要

Provided is a group III nitride crystal substrate (1), wherein the crystal substrate is represented by the value |d1-d2|/d2 when d1 is the interplanar spacing at an X-ray penetration depth of 0.3 µm and d2 is the interplanar spacing at an X-ray penetration depth of 5 µm in terms of the interplanar spacings of specific parallel crystal lattice planes obtained by X-ray diffraction measurement in which the X-ray penetration depth from a primary surface (1s) of the crystal substrate is varied while the X-ray diffraction conditions for any specific parallel crystal lattice plane of the group III nitride crystal substrate (1) are satisfied; the uniform distortion of the surface layer of the crystal substrate is 1.7×10-3, and the plane orientation of the primary surface (1s) has an angle of inclination between -10º and 10º in the [0001] direction from a plane (1v), which includes a c axis (1c), of the crystal substrate. A group III nitride crystal substrate, a group III nitride crystal substrate having an epitaxial layer, and a semiconductor device and method for producing the same, which are ideal for the production of a light-emitting device wherein blue shift of the emitted light is controlled, are therefore provided.