An impurity concentration C is the optimum concentration of {HEAD ~ lightly doped diffusion regions} that achieves {TAIL ~ the lowest hot carrier effect} 
achieves
An impurity concentration C is the optimum concentration of { HEAD ~ lightly doped diffusion regions } that achieves { TAIL ~ the lowest hot carrier effect }
OTH OTH OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD HEAD HEAD OTH REL TAIL TAIL TAIL TAIL TAIL TAIL TAIL TAIL TAIL