This is done by forming a pinned photodiode which has {HEAD ~ a selective connection} to {TAIL ~ the substrate} 
to
This is done by forming a pinned photodiode which has { HEAD ~ a selective connection } to { TAIL ~ the substrate }
OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD HEAD REL TAIL TAIL TAIL TAIL TAIL TAIL