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, wherein the Group III nitride semiconductor is grown on the seed substrate, while controlling the surface modification weight ratio, which is defined as the ratio of the weight of Na including a portion surface-modified through oxidation or hydroxidation to the weight of Na when the surface thereof has no surface-modified portion as a reference weight, with Na serving as the flux.

What is claimed is: 
     
         1 . A method for producing a Group III nitride semiconductor 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 the Group III nitride semiconductor is grown on the seed substrate, while controlling the surface modification weight ratio, which is defined as the ratio of the weight of Na including a portion surface-modified through oxidation or hydroxidation to the weight of Na when the surface thereof has no surface-modified portion as a reference weight, with Na serving as the flux. 
     
     
         2 . The Group III nitride semiconductor production method according to  claim 1 , wherein the surface modification weight ratio is 1.000002 to 1.001. 
     
     
         3 . The Group III nitride semiconductor production method according to  claim 1 , wherein the surface modification weight ratio is 1.00002 to 1.0001. 
     
     
         4 . The Group III nitride semiconductor production method according to  claim 1 , wherein the surface modification weight ratio is 1.000002 to 1.00005. 
     
     
         5 . The Group III nitride semiconductor production method according to  claim 1 , wherein the surface modification weight ratio is modified by maintaining Na in a specific environment outside the furnace before its entrance to the furnace. 
     
     
         6 . The Group III nitride semiconductor production method according to  claim 1 , wherein the surface modification weight ratio is modified by feeding a gas mixture containing at least one of oxygen and water to the furnace. 
     
     
         7 . The Group III nitride semiconductor production method according to  claim 5 , wherein at least one of the oxygen concentration and the water content of the specific environment are controlled to ≤0.05 ppm and >0 ppm, respectively. 
     
     
         8 . The Group III nitride semiconductor production method according to  claim 5 , wherein a gas mixture containing at least one of oxygen and water may be introduced to the specific environment. 
     
     
         9 . The Group III nitride semiconductor production method according to  claim 1 , wherein an Na piece whose surface modification weight ratio has been controlled is cut, and a carbon material is placed on a surface of the cut piece which has undergone no oxidation or hydroxidation, followed by placing the resultant piece in the furnace.