The method 6, wherein {HEAD ~ the first refractive index adjustment layer} is formed on the n type nitride semiconductor layer and has {TAIL ~ a refractive index} less than that of the n type nitride semiconductor layer, and 
has
The method 6 , wherein { HEAD ~ the first refractive index adjustment layer } is formed on the n type nitride semiconductor layer and has { TAIL ~ a refractive index } less than that of the n type nitride semiconductor layer , and
OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD HEAD HEAD HEAD HEAD OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH REL TAIL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH