The method 12, wherein {HEAD ~ the boron doped region} is formed by {TAIL ~ solid state diffusion} and etching 
is formed by
The method 12 , wherein { HEAD ~ the boron doped region } is formed by { TAIL ~ solid state diffusion } and etching
OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD HEAD HEAD REL REL REL TAIL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH