{HEAD ~ The first and second electrodes} are separately disposed on the epitaxial layer structure, and the epitaxial layer structure has a RMS roughness less than 3 nm on {TAIL ~ a surface} wherein the second electrode is formed 
{ HEAD ~ The first and second electrodes } are separately disposed on the epitaxial layer structure , and the epitaxial layer structure has a RMS roughness less than 3 nm on { TAIL ~ a surface } wherein the second electrode is formed
HEAD HEAD HEAD HEAD HEAD HEAD HEAD HEAD HEAD OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH