Question

Why copper is preferred as interconnected material over aluminum?

Answer 1

-a great advantage of copper interconnects is its low electrical resistivity in comparision to aluminium interconnects. The electric resistivity offer to conduction by copper is approximately 40% less than corresponding aluminium intercoonects. As a result a speed advantage of over 15% is seen with copper interconnects in microprocessors as compared to the aluminum intercoonects.

- electromigration occurs less frequently in copper than in aluminium. This phenomenon is known to cause short circuit and open circuit failures due to the creation of voids and hillocks.

- high packing density is possible due to possiblity of reducing interconnect dimensions in copper more than aluminium.