depositing a diffusion source layer comprising {HEAD ~ the impurity species} of {TAIL ~ Si} or Ge on the surface of said structure in the presence of an source of As, P or Sb heavily doping said layer in the range of 5 to 20 by atomic percent, 
depositing a diffusion source layer comprising { HEAD ~ the impurity species } of { TAIL ~ Si } or Ge on the surface of said structure in the presence of an source of As , P or Sb heavily doping said layer in the range of 5 to 20 by atomic percent ,
OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD HEAD REL 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 OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH