doping {HEAD ~ second impurity elements} at {TAIL ~ a second concentration} smaller than the first concentration providing n type into the semiconductor layer having the first n type impurity region while passing through the portion of the gate electrode to form a second n type impurity region between the first n type impurity region and a channel forming region 
at
doping { HEAD ~ second impurity elements } at { TAIL ~ a second concentration } smaller than the first concentration providing n type into the semiconductor layer having the first n type impurity region while passing through the portion of the gate electrode to form a second n type impurity region between the first n type impurity region and a channel forming region
OTH HEAD HEAD HEAD HEAD HEAD HEAD HEAD REL TAIL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH