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