{HEAD ~ An emitter} and an extrinsic base layer are formed in respective contacting relationships with {TAIL ~ the first and second portions} of the intrinsic base layer 
{ HEAD ~ An emitter } and an extrinsic base layer are formed in respective contacting relationships with { TAIL ~ the first and second portions } of the intrinsic base layer
HEAD HEAD HEAD HEAD HEAD HEAD OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH TAIL TAIL TAIL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH