doping first impurity elements at a first concentration providing n type into the semiconductor layer using {HEAD ~ the gate electrode} as {TAIL ~ a mask} to form a first n type impurity region 
as
doping first impurity elements at a first concentration providing n type into the semiconductor layer using { HEAD ~ the gate electrode } as { TAIL ~ a mask } to form a first n type impurity region
OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD HEAD REL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH OTH