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