The spacer is preferably tapered and the via may include a glue layer to improve {HEAD ~ the adherence} of the spacer to {TAIL ~ the dielectric layer} 
to
The spacer is preferably tapered and the via may include a glue layer to improve { HEAD ~ the adherence } of the spacer to { TAIL ~ the dielectric layer }
OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD OTH OTH OTH REL TAIL TAIL TAIL TAIL TAIL TAIL TAIL