The magnitude of {HEAD ~ the current} exceeding {TAIL ~ the threshold current density} initiates electromigration of the source/drain silicide into the channel region, such that the source/drain of the FET is shorted to the substrate after programming 
The magnitude of { HEAD ~ the current } exceeding { TAIL ~ the threshold current density } initiates electromigration of the source / drain silicide into the channel region , such that the source / drain of the FET is shorted to the substrate after programming
OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD REL TAIL TAIL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH