Patent ID: 7416604

Claim:
A semiconductor device comprising, a nitride crystal substrate, or an epilayer-containing nitride crystal substrate including one or more semiconductor layer(s) formed by epitaxial growth on at least one of main surface sides of said nitride crystal substrate, and one or more semiconductor layer(s) formed by epitaxial growth on at least one of the main surface sides of said nitride crystal substrate or said epilayer-containing nitride crystal substrate, wherein in connection with plane spacing of arbitrary specific parallel crystal lattice planes of said nitride crystal substrate obtained from X-ray diffraction measurement performed with variation of X-ray penetration depth from a surface of said crystal while X-ray diffraction conditions of said specific parallel crystal lattice planes being satisfied, a uniform distortion at a surface layer of said crystal substrate represented by a value of |d 1 −d 2 |/d 2 obtained from said plane spacing d 1 at said X-ray penetration depth of 0.3 μm and said plane spacing d 2 at the X-ray penetration depth of 5 μm is equal to or lower than 2.1×10 −3 .