| abstract |
A group III nitride crystal substrate suitable for manufacturing a light emitting device in which blue shift of light emission is suppressed, a group III nitride crystal substrate with an epi layer, a semiconductor device, and a method for manufacturing the same are provided. The group III nitride crystal substrate 1 has an X-ray penetration depth from a main surface 1s of the crystal substrate while satisfying an X-ray diffraction condition of an arbitrary specific crystal lattice plane of the group III nitride crystal substrate 1. In the plane spacing of the specific crystal lattice plane obtained from the changing X-ray diffraction measurement, it is obtained from the plane spacing d 1 at the X-ray penetration depth of 0.3 μm and the spacing d 2 at the X-ray penetration depth of 5 μm. The uniform distortion of the surface layer of the crystal substrate represented by the value of d 1 −d 2 | / d 2 is 1.7 × 10 −3 or less, and the plane orientation of the main surface includes the c-axis of the crystal substrate In the [0001] direction from -10 ° to 10 °. [Selection] Figure 6 |