Method and system for formation of p-n junctions in gallium nitride based electronics

Abstract

A semiconductor device includes a III-nitride substrate having a first conductivity type and a first electrode electrically coupled to the III-nitride substrate. The semiconductor device also includes a III-nitride material having a second conductivity type coupled to the III-nitride substrate at a regrowth interface and a p-n junction disposed between the III-nitride substrate and the regrowth interface.

1 . A semiconductor device comprising:
 a III-nitride substrate having a first conductivity type;   a first electrode electrically coupled to the III-nitride substrate;   a III-nitride material having a second conductivity type coupled to the III-nitride substrate at a regrowth interface; and   a p-n junction disposed between the III-nitride substrate and the regrowth interface.   
     
     
         2 . The semiconductor device of  claim 1  further comprising a second electrode electrically coupled to the III-nitride material having the second conductivity type. 
     
     
         3 . The semiconductor device of  claim 1  wherein a structural defect concentration associated with the lateral p-n junction is less than a structural defect concentration associated with a region laterally adjacent the lateral p-n junction. 
     
     
         4 . The semiconductor device of  claim 1  wherein the III-nitride substrate comprises an n-type GaN material. 
     
     
         5 . The semiconductor device of  claim 1  wherein the III-nitride material having the second conductivity type comprises a p-type GaN material. 
     
     
         6 . The semiconductor device of  claim 5  wherein the III-nitride material having the second conductivity type comprises an acceptor diffused region disposed between the regrowth interface and the p-n junction. 
     
     
         7 . The semiconductor device of  claim 6  wherein the acceptor region comprises a diffusion region including at least one of zinc, magnesium, beryllium, or calcium. 
     
     
         8 . The semiconductor device of  claim 1  wherein the p-n junction extends in a direction substantially orthogonal to a growth direction of the III-nitride material having the second conductivity type. 
     
     
         9 . The semiconductor device of  claim 1  wherein the III-nitride substrate is characterized by a growth surface substantially coplanar with a surface of the first electrode. 
     
     
         10 . A method of fabricating a lateral p-n junction, the method comprising:
 providing a III-nitride substrate having a first conductivity type;   forming a diffusion mask over a predetermined portion of the III-nitride substrate;   forming a dopant source including a dopant in contact with at least an exposed portion of the III-nitride substrate; and   diffusing the dopant into the III-nitride substrate to form a diffusion region having a second conductivity type different from the first conductivity type.   
     
     
         11 . The method of  claim 10  wherein a spatial orientation of a p-n junction between the III-nitride substrate and the diffusion region is substantially orthogonal to a growth direction of the III-nitride substrate. 
     
     
         12 . The method of  claim 10  wherein the III-nitride substrate comprises a GaN substrate doped with at least one of silicon or oxygen. 
     
     
         13 . The method of  claim 12  wherein the dopant comprises zinc. 
     
     
         14 . The method of  claim 10  wherein the dopant source comprises zinc oxide. 
     
     
         15 . The method of  claim 10  wherein the dopant source comprises a source of at least one of magnesium, beryllium, or calcium.