Group iii nitrides on nanopatterned substrates

Abstract

A patterned substrate is provided having at least two mesa surface portions, and a recessed surface located beneath and positioned between the at least two mesa surface portions. A Group III nitride material is grown atop the mesa surface portions of the patterned substrate and atop the recessed surface. Growth of the Group III nitride material is continued merging the Group III nitride material that is grown atop the mesa surface portions. When the Group III nitride material located atop the mesa surface portions merge, the Group III nitride material growth on the recessed surface ceases. The merged Group III nitride material forms a first Group III nitride material structure, and the Group III nitride material formed in the recessed surface forms a second material structure. The first and second material structures are disjoined from each other and are separated by an air gap.

What is claimed is: 
     
         1 . A semiconductor structure comprising:
 a Group III nitride material structure comprising a Group III nitride material and having a planar uppermost surface and a corrugated bottommost surface opposing the planar uppermost surface, wherein said corrugated bottommost surface comprises at least two non-indented portions, and having an indented portion located between said at least two non-indented portions.   
     
     
         2 . The semiconductor structure of  claim 1 , further comprising at least one semiconductor device located on the planar uppermost surface of the Group III nitride material structure. 
     
     
         3 . The semiconductor structure of  claim 2 , further comprising another substrate located on an exposed uppermost surface of the at least one semiconductor device. 
     
     
         4 . The semiconductor structure of  claim 1 , wherein said corrugated bottommost surface is bare. 
     
     
         5 . The semiconductor structure of  claim 1 , wherein said each non-indented portion of the corrugated bottommost surface is in direct contact with a mesa surface portion of a patterned substrate. 
     
     
         6 . The semiconductor structure of  claim 5 , further comprising a second Group III nitride material structure located atop a recessed surface of the patterned substrate, said recessed surface is present in a recessed opening located in said patterned substrate and separates two neighboring mesa surface portions of the patterned substrate. 
     
     
         7 . The semiconductor structure of  claim 1 , wherein said each non-indented portion of the corrugated bottommost surface is in direct contact with a first portion of a buffer layer. 
     
     
         8 . The semiconductor structure of  claim 7 , further comprising a second Group III nitride material structure located on a second portion of the buffer layer, wherein said second portion of the buffer layer is vertically offset and beneath said first portion of the buffer layer. 
     
     
         9 . The semiconductor structure of  claim 8 , further comprising a patterned substrate located beneath said buffer layer. 
     
     
         10 . The semiconductor structure of  claim 1 , wherein said Group III nitride material comprises gallium nitride or aluminum nitride.