doping second impurity elements at 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 {HEAD ~ a second n type impurity region} between {TAIL ~ the first n type impurity region} and a channel forming region 
doping second impurity elements at 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 { HEAD ~ a second n type impurity region } between { TAIL ~ the first n type impurity region } and a channel forming region
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 HEAD HEAD HEAD HEAD HEAD HEAD HEAD HEAD HEAD HEAD REL TAIL TAIL TAIL TAIL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH