Group III-nitride layers with patterned surfaces
View Patent ↗A fabrication method produces a mechanically patterned layer of group III-nitride. The method includes providing a crystalline substrate and forming a first layer of a first group III-nitride on a planar surface of the substrate. The first layer has a single polarity and also has a pattern of holes or trenches that expose a portion of the substrate. The method includes then, epitaxially growing a second layer of a second group III-nitride over the first layer and the exposed portion of substrate. The first and second group III-nitrides have different alloy compositions. The method also includes subjecting the second layer to an aqueous solution of base to mechanically pattern the second layer.
1. An apparatus, comprising:
a layer of group Ill-nitride having a top surface, the top surface having a plurality of pyramidal structures of the group Ill-nitride; and
an electrode located directly on the layer between portions of the layer having the pyramidal structures; and
wherein the pyramidal structures of the top surface are physically separated from any electrode.
2. The apparatus of claim 1 , wherein the electrode is located on a flat portion of the top surface.
3. The apparatus of claim 1 , wherein the group III-nitride comprises gallium.
4. The apparatus of claim 3 , wherein the electrode is located on a flat portion of the top surface.
5. The apparatus of claim 4 , wherein tips of the pyramidal structures have a random distribution.
6. The apparatus of claim 1 , wherein the pyramidal structures spatially overlap.
7. The apparatus of claim 1 , wherein tips of the pyramidal structures have a random distribution.
8. The apparatus of claim 1 , wherein the electrode is located on a flat portion of a surface of the layer.
9. An apparatus, comprising:
a layer of group Ill-nitride having a top surface, the top surface having a plurality of pyramidal structures of the group III-nitride;
an electrode located directly on the layer between portions of the layer having the pyramidal structures; and
a crystalline layer of another group Ill-nitride alloy; and
wherein a portion of the layer of the group Ill-nitride is located on the layer of the another group Ill-nitride alloy.
10. The apparatus of claim 9 , wherein the pyramidal structures of the top surface are physically separated from any electrode.