The method 1, wherein {HEAD ~ the buried layer} is formed with {TAIL ~ a higher dopant concentration} than the semiconductor layer 
is formed with
The method 1 , wherein { HEAD ~ the buried layer } is formed with { TAIL ~ a higher dopant concentration } than the semiconductor layer
OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD HEAD REL REL REL TAIL TAIL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH