The doped regions can be formed by implanting {HEAD ~ first type dopants} into {TAIL ~ the substrate} 
The doped regions can be formed by implanting { HEAD ~ first type dopants } into { TAIL ~ the substrate }
OTH OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD HEAD REL TAIL TAIL TAIL TAIL TAIL TAIL