{HEAD ~ A second ion implantation} is carried out under {TAIL ~ the conditions} of a concentration of about 5.0×1015 ions/cm2 and an acceleration energy of about 40 KeV using As+ ions serving as carriers 
is carried out under
{ HEAD ~ A second ion implantation } is carried out under { TAIL ~ the conditions } of a concentration of about 5.0×1015 ions / cm2 and an acceleration energy of about 40 KeV using As+ ions serving as carriers
HEAD HEAD HEAD HEAD HEAD HEAD HEAD HEAD REL REL REL REL 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