Only one additional mask is needed to fabricate {HEAD ~ this device} in addition to {TAIL ~ the others} normally encountered in a VLSI logic process 
Only one additional mask is needed to fabricate { HEAD ~ this device } in addition to { TAIL ~ the others } normally encountered in a VLSI logic process
OTH OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD OTH OTH OTH TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH