Method for producing a group iii nitride semiconductor

Abstract

A method for producing a Group III nitride semiconductor includes feeding a nitrogen-containing gas into a molten mixture of a Group III metal and a flux placed in a furnace, to thereby grow a Group III nitride semiconductor on a seed substrate. At least an oxidation amount of Na, serving as the flux, is controlled outside the furnace, and the controlled Na is fed into the furnace.

What is claimed is: 
     
         1 . A method for producing a Group III nitride semiconductor, the method comprising:
 feeding a nitrogen-containing gas into a molten mixture of a Group III metal and a flux placed in a furnace, to thereby grow a Group III nitride semiconductor on a seed substrate,   wherein at least an oxidation amount of Na, serving as the flux, is controlled outside the furnace, and the controlled Na is fed into the furnace.   
     
     
         2 . The method for producing the Group III nitride semiconductor production according to  claim 1 , wherein molten Na, prepared by liquefying Na, is circulated through a first state where the temperature is maintained at a first temperature and a second state where a temperature is maintained at a second temperature lower than the first temperature, whereby oxidized Na, contained in the molten Na, is removed in the second state, and the oxidation amount of Na is regulated by modifying the second temperature. 
     
     
         3 . The method for producing the Group III nitride semiconductor production according to  claim 2 , wherein the second temperature is controlled in a range from 120° C. to 300° C. 
     
     
         4 . The method for producing the Group III nitride semiconductor production according to  claim 3 , wherein circulation of molten Na, performed for controlling the oxidation amount of Na and purity of Na, is conducted by a circulation apparatus,
 wherein the Na circulation apparatus includes a circulation path for converting an Na material to liquid and causing the liquid to flow, and   wherein the circulation path includes an Na purity control section maintained at the second temperature and a pipe.   
     
     
         5 . The method for producing the Group III nitride semiconductor production according to  claim 4 , wherein the Na circulation path includes an Na-storing section, and temperatures of the Na-storing section and the pipe are adjusted to be higher than the temperature of the Na purity control section.