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