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