Single step pendeo-and lateral epitaxial overgrowth of group III-nitride epitaxial layers with group III-nitride buffer layer and resulting structures

A method of fabricating a gallium nitride-based semiconductor structure on a substrate, the method comprising:

• forming at least one trench in a substrate to thereby define both the trench and a raised portion immediately adjacent the trench;
• forming a mask on the trenched substrate with the mask having at least one opening therein on the raised portion of the substrate;
• growing a buffer layer on the raised portion of the substrate through the opening in the mask;
• and
• growing an epitaxial layer selected from the group consisting of gallium nitride and Group III nitride alloys of gallium nitride upwardly from the buffer layer and laterally across the trench.

A method of fabricating a gallium nitride-based semiconductor structure on a substrate, the method comprising:

• forming a mask on a substrate that includes bath at least one trench and at least two raised portions adjacent said trench, and with said mask having at least one opening therein on said raised portion of said substrate;
• growing a buffer layer on said raised portion of said substrate within said opening in said mask;
• and
• growing an epitaxial layer selected from the group consisting of gallium nitride and Group III nitride alloys of gallium nitride upwardly from said buffer layer and laterally across said trench until it coalesces over said trench.

A method of fabricating a gallium nitride-based semiconductor structure on a substrate, the method comprising:

• forming at least one trench in a substrate to thereby define both the trench and at least two raised portions immediately adjacent the trench;
• forming a mask on the trenched substrate with the mask having at least one opening therein on the raised portion of the substrate;
• growing a buffer layer on the raised portion of the substrate through the opening in the mask;
• and
• growing an epitaxial layer selected from the group consisting of gallium nitride and Group III nitride alloys of gallium nitride upwardly from the buffet layer and laterally across the trench until it coalesces over the trench.