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

Abstract

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 |d 1 −d 2 |/d 2 obtained from the plane spacing d 1 at the X-ray penetration depth of 0.3 μm and the plane spacing d 2 at the X-ray penetration depth of 5 μm is equal to or lower than 2.1×10 −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.

1 - 14 . (canceled) 
   
   
       15 . 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 the nitride crystal 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 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 , and   wherein said surface of said crystal has a surface roughness Ra of 3 nm or lower.   
   
   
       16 . 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, a light-emitting element including three or more semiconductor layers formed by epitaxial growth on one of the main surface sides of said nitride crystal substrate or said epilayer-containing nitride crystal substrate, a first electrode formed on the other main surface side of said nitride crystal substrate or said epilayer-containing nitride crystal substrate, a second electrode formed on the outermost semiconductor layer among said plurality of semiconductor layers, a conductor bearing said light-emitting element; and a substrate side of said light emitting element is a light emitting side, an outermost semiconductor layer side is a mount aide, and said plurality of semiconductor layers include a p-type semiconductor layer, an n-type semiconductor layer and a light emitting layer formed between these conductive semiconductor layers,   wherein 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 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 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 , and   wherein said surface of said crystal has a surface roughness Ra of 3 nm or lower.