{TAIL ~ A source/drain impurity area} may be formed over a second silicon layer on both sides of {HEAD ~ a gate electrode} 
{ TAIL ~ A source / drain impurity area } may be formed over a second silicon layer on both sides of { HEAD ~ a gate electrode }
TAIL TAIL TAIL 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