This will retard phosphorus from diffusing into an overlying epitaxial layer and retard {HEAD ~ other layers} formed on {TAIL ~ the substrate} from being auto doped 
formed on
This will retard phosphorus from diffusing into an overlying epitaxial layer and retard { HEAD ~ other layers } formed on { TAIL ~ the substrate } from being auto doped
OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD REL REL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH