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