The first and second electrodes are separately disposed on the epitaxial layer structure, and {HEAD ~ the epitaxial layer structure} has {TAIL ~ a root means square roughness} less than about 3 at a surface whereon the first electrode is formed 
has
The first and second electrodes are separately disposed on the epitaxial layer structure , and { HEAD ~ the epitaxial layer structure } has { TAIL ~ a root means square roughness } less than about 3 at a surface whereon the first electrode is formed
OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD HEAD HEAD REL TAIL TAIL TAIL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH