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