Group iii nitride crystal substrate, epilayer-containing group iii nitride crystal substrate, semiconductor device and method of manufacturing the same

A method of manufacturing a semiconductor device, comprising the steps of:

• preparing a group III nitride crystal substrate, wherein,
• a plane spacing of arbitrary specific parallel crystal lattice planes of said crystal substrate being obtained from X-ray diffraction measurement performed with variation of X-ray penetration depth from a main surface of said crystal substrate while X-ray diffraction conditions of said specific parallel crystal lattice planes of said crystal substrate are satisfied,
• a uniform distortion at a surface layer of said crystal substrate represented by a value of |d1−d2|/d2 is equal to or lower than 1.7×10−3 where d1 indicates a plane spacing at said X-ray penetration depth of 0.3 μm and d2 indicates a plane spacing at said X-ray penetration depth of 5 μm, and wherein
• a plane orientation of said main surface has an inclination angle equal to or greater than −10° and equal to or smaller than 10° in a [0001] direction with respect to a plane including a c axis of said crystal substrate;
• and
• epitaxially growing at least one semiconductor layer on said main surface of said crystal substrate, thereby forming an epilayer-containing group III nitride crystal substrate.

A method of manufacturing a semiconductor device, comprising the steps of:

• preparing a group III nitride crystal substrate, wherein,
• on a diffraction intensity profile of arbitrary specific parallel crystal lattice planes of said crystal substrate being obtained from X-ray diffraction measurement performed with variation of X-ray penetration depth from a main surface (1s) of said crystal substrate while X-ray diffraction conditions of said specific parallel crystal lattice planes are satisfied,
• an irregular distortion at a surface layer of said crystal substrate represented by a value of |v1−v2| obtained from a half value width v1 of a diffraction intensity peak at said X-ray penetration depth of 0.3 μm and a half value width v2 of the diffraction intensity peak at said X-ray penetration depth of 5 μm is equal to or lower than 110 arcsec, and wherein
• a plane orientation of said main surface has an inclination angle equal to or greater than −10° and equal to or smaller than 10° in a [0001] direction with respect to a plane including a c axis of said crystal substrate;
• and
• epitaxially growing at least one semiconductor layer on said main surface of said crystal substrate, thereby forming an epilayer-containing group III nitride crystal substrate.

A method of manufacturing a semiconductor device, comprising the steps of:

• preparing a group III nitride crystal substrate, wherein,
• on a rocking curve being measured by varying an X-ray penetration depth from a main surface of said crystal substrate in connection with X-ray diffraction of arbitrary specific parallel crystal lattice planes of said crystal substrate,
• a plane orientation deviation of said specific parallel crystal lattice planes of a surface layer of said crystal substrate represented by a value of |w1−w2| obtained from a half value width w1 of a diffraction intensity peak at said X-ray penetration depth of 0.3 μm and a half value width w2 of the diffraction intensity peak at said X-ray penetration depth of 5 μm is equal to or lower than 300 arcsec, and wherein
• a plane orientation of said main surface has an inclination angle equal to or greater than −10° and equal to or smaller than 10° in a [0001] direction with respect to a plane including a c axis of said crystal substrate;
• and
• forming an epilayer-containing group III nitride crystal substrate by epitaxially growing at least one semiconductor layer on said main surface of said crystal substrate.