Method for producing n-type group iii nitride single crystal, n-type group iii nitride single crystal, and crystal substrate

Abstract

A method of producing an n-type group III nitride single crystal includes putting raw materials that include at least a substance including a group III element, an alkali metal, and boron oxide into a reaction vessel; melting the boron oxide by heating the reaction vessel to a melting point of the boron oxide; forming a mixed melt which includes the group III element, the alkali metal, and the boron oxide, in the reaction vessel by heating the reaction vessel to a crystal growth temperature of a group III nitride; dissolving nitrogen into the mixed melt by bringing a nitrogen-containing gas into contact with the mixed melt; and growing an n-type group III nitride single crystal, which is doped with oxygen as a donor, from the group III element, the nitrogen, and oxygen in the boron oxide that are dissolved in the mixed melt.

1 - 6 . (canceled) 
     
     
         7 . An n-type group III nitride single crystal that is doped with oxygen to a concentration of 10 17  cm −3  or more and doped with boron to a concentration of 10 17  cm −3  or more. 
     
     
         8 . The n-type group III nitride single crystal according to  claim 7 , wherein the oxygen concentration of the n-type group III nitride single crystal is 10 18  cm −3  or more. 
     
     
         9 . The n-type group III nitride single crystal according to  claim 7 , wherein the boron concentration of the n-type group III nitride single crystal is 10 18  cm −3  or more. 
     
     
         10 . A crystal substrate comprising an n-type group III nitride single crystal that is doped with oxygen to a concentration of 10 17  cm −3  or more and doped with boron to a concentration of 10 17  cm −3  or more. 
     
     
         11 . The crystal substrate according to  claim 10 , wherein the oxygen concentration of the n-type group III nitride single crystal is 10 18  cm −3  or more. 
     
     
         12 . The crystal substrate according to  claim 10 , wherein the boron concentration of the n-type group III nitride single crystal is 10 18  cm −3  or more.