As a consequence of the masking, {TAIL ~ the second portion} of the intrinsic base layer is thinner than the first portion of {HEAD ~ the intrinsic base layer} 
As a consequence of the masking , { TAIL ~ the second portion } of the intrinsic base layer is thinner than the first portion of { HEAD ~ the intrinsic base layer }
OTH OTH OTH OTH OTH OTH OTH TAIL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD HEAD HEAD