Nitride crystal and method for producing the same

Abstract

A nitride crystal which encircles an outer periphery of a seed crystal, the nitride crystal in an embodiment includes: a first partial region, and a second partial region that has optical characteristics different from those of the first partial region and has optical characteristics which indicate the crystal orientation.

1 - 9 . (canceled) 
     
     
         10 . A method for producing a nitride crystal, the method comprising:
 (a) forming a mixed molten liquid of an alkali metal and a substance including at least a Group III element in a reaction vessel;   (b) installing a seed crystal inside the reaction vessel;   (c) growing a Group III nitride crystal in the mixed molten liquid and the nitrogen dissolved into the mixed molten liquid, from the seed crystal, by bringing a gas containing nitrogen into contact with the mixed molten liquid and by dissolving the nitrogen in the gas into the mixed molten liquid;   (d) fluctuating a condition for crystal growth; and   (e) forming a first partial region and a second partial region within the nitride crystal.   
     
     
         11 . The method for producing a nitride crystal according to  claim 10 ,
 wherein (d) comprises   fluctuating the nitrogen partial pressure in the gas during the crystal growth of the nitride crystal so as to form the first partial region and the second partial region.   
     
     
         12 . The method for producing a nitride crystal according to  claim 10 ,
 wherein (d) comprises   fluctuating the temperature of the mixed molten liquid during the crystal growth of the nitride crystal so as to form the first partial region and the second partial region.   
     
     
         13 . The method for producing a nitride crystal according to  claim 11 ,
 wherein the fluctuating the nitrogen partial pressure is carried out immediately before a termination of the growing the nitride crystal.   
     
     
         14 . The method for producing a nitride crystal according to  claim 12 ,
 wherein the fluctuating the temperature of the mixed molten liquid is carried out immediately before a termination of the growing the nitride crystal.   
     
     
         15 . The method for producing a nitride crystal according to  claim 10 ,
 wherein the forming a mixed molten liquid further comprises adding an additive into the reaction vessel so as to form the mixed molten liquid.   
     
     
         16 . The method for producing a nitride crystal according to  claim 15 ,
 wherein the forming a mixed molten liquid comprises adding an additive into the mixed molten liquid by eluting a component of the reaction vessel from an inner wall surfaces of the reaction vessel.   
     
     
         17 . The method for producing a nitride crystal according to  claim 10 ,
 wherein plural first partial regions are formed in (e) and the second partial region is a plane region positioned between two of the plural first partial regions, and   the second partial region has optical characteristics different from those of the first partial regions.