Method and system for gallium nitride electronic devices using engineered substrates

Abstract

A method for fabricating an electronic device includes providing an engineered substrate structure comprising a III-nitride seed layer, forming GaN-based functional layers coupled to the III-nitride seed layer, and forming a first electrode structure electrically coupled to at least a portion of the GaN-based functional layers. The method also includes joining a carrier substrate opposing the GaN-based functional layers and removing at least a portion of the engineered substrate structure. The method further includes forming a second electrode structure electrically coupled to at least another portion of the GaN-based functional layers and removing the carrier substrate.

What is claimed is: 
     
         1 . A method for fabricating an electronic device, the method comprising:
 providing an engineered substrate structure comprising a III-nitride seed layer;   forming GaN-based functional layers coupled to the III-nitride seed layer;   forming a first electrode structure electrically coupled to at least a portion of the GaN-based functional layers;   joining a carrier substrate opposing the GaN-based functional layers;   removing at least a portion of the engineered substrate structure;   forming a second electrode structure electrically coupled to at least another portion of the GaN-based functional layers; and   removing the carrier substrate.   
     
     
         2 . The method of  claim 1  further comprising joining a device substrate to the second electrode prior to removing the carrier substrate. 
     
     
         3 . The method of  claim 1  wherein the III-nitride seed layer comprises a GaN material. 
     
     
         4 . The method of  claim 1  wherein the III-nitride seed layer comprises an n-type GaN-based material. 
     
     
         5 . The method of  claim 1  further comprising epitaxially growing a III-nitride buffer layer coupled to the III-nitride seed layer and a III-nitride drift layer coupled to the III-nitride buffer layer. 
     
     
         6 . The method of  claim 5  wherein forming GaN-based functional layers comprises epitaxially growing the GaN-based functional layers. 
     
     
         7 . The method of  claim 1  wherein joining the carrier wafer to the GaN-based functional layers comprises:
 forming an electrode structure coupled to at least a portion of one of the GaN-based functional layers; 
 forming a sacrificial bonding layer coupled to another portion of the one of the GaN-based functional layers and at least a portion of the electrode structure; and 
 bonding the carrier wafer to the sacrificial bonding layer. 
 
     
     
         8 . The method of  claim 7  wherein removing the carrier substrate comprises removing the sacrificial bonding layer. 
     
     
         9 . The method of  claim 1  wherein the engineered substrate comprises a handle wafer and a bonding layer coupled to the III-nitride seed layer, and wherein removing at least a portion of the engineered substrate structure comprises mechanically removing the handle wafer, chemically etching the bonding layer, and physically etching the III-nitride seed layer.