A thickness of about 700 to 900 Å of {HEAD ~ a silicon nitride film} is suitable for {TAIL ~ a refractive index} of about 1.9 to 2.0 
A thickness of about 700 to 900 Å of { HEAD ~ a silicon nitride film } is suitable for { TAIL ~ a refractive index } of about 1.9 to 2.0
OTH OTH OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD HEAD HEAD OTH OTH OTH TAIL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH