The metallic layer 29 is obtained by using {HEAD ~ such a conventional technique} as sputtering or {TAIL ~ thermal evaporation} 
as
The metallic layer 29 is obtained by using { HEAD ~ such a conventional technique } as sputtering or { TAIL ~ thermal evaporation }
OTH OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD HEAD HEAD REL OTH OTH TAIL TAIL TAIL TAIL TAIL TAIL