Refueling: Preventing Wire Degradation due to Electromigration

Electromigration is a major source of wire and via failure. Refueling undoes EM for bidirectional wires and power/ground grids—some of a chip's most vulnerable wires. Refueling exploits EM's self-healing effect by balancing the amount of current flowing in both directions of a wire. It can significantly extend a wire's lifetime while reducing the chip area devoted to wires.