A passivation capping layer overlies {HEAD ~ the ohmic contact} and has an oxidation rate which is less than the oxidation rate of {TAIL ~ the ohmic contact} 
A passivation capping layer overlies { HEAD ~ the ohmic contact } and has an oxidation rate which is less than the oxidation rate of { TAIL ~ the ohmic contact }
OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD HEAD OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH TAIL TAIL TAIL TAIL TAIL TAIL TAIL