Current Crowding Effects at Aluminun-Silicon Contacts

The magnitude of current crowding and its effects on failure mechanisms at aluminum-silicon contacts have been studied by using an enlarged contact. Current was found to decrease exponentially with distance from the leading edge of the contact. Joule heating in the contact when stressed at high currents caused diffusion of silicon into the aluminum metallization. Accelerated testing at low currents to minimize this effect resulted in diffusion barrier type failures.