Nitride crystal, nitride crystal substrate, epilayer-containing nitride crystal substrate, semiconductor device and method of manufacturing the same

摘要

A nitride crystal is characterized in that, in connection with plane spacing of arbitrary specific parallel crystal lattice planes of the nitride crystal obtained from X-ray diffraction measurement performed with variation of X-ray penetration depth from a surface of the crystal while X-ray diffraction conditions of the specific parallel crystal lattice planes are satisfied, a uniform distortion at a surface layer of the crystal represented by a value of |d₁-d₂|/d₂ obtained from the plane spacing d₁ at the X-ray penetration depth of 0.3 mum and the plane spacing d₂ at the X-ray penetration depth of 5 mum is equal to or lower than 2.1x10^-3. The above configuration provides the nitride crystal having a crystal surface layer that is evaluated directly and reliably without breaking the crystal so that it can be used in a preferred fashion as a substrate for a semiconductor device as well as the nitride crystal substrate, an epilayer-containing nitride crystal substrate, a semiconductor device and a method of manufacturing the same.