{HEAD ~ The collar layer} 12 is, thereupon, removed in {TAIL ~ the upper region} and removed laterally down to the upper edge of the second polysilicon layer 13 
is removed in
{ HEAD ~ The collar layer } 12 is , thereupon , removed in { TAIL ~ the upper region } and removed laterally down to the upper edge of the second polysilicon layer 13
HEAD HEAD HEAD HEAD HEAD HEAD HEAD OTH REL OTH OTH OTH REL REL TAIL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH