The effect of interconnect scaling and low-k dielectric on the thermal characteristics of the IC metal

The effect of interconnect scaling and low-k dielectric on the thermal characteristics of interconnect structures has been characterized for the first time under DC and pulsed current conditions. It is shown that under DC conditions the thermal impedance of metal lines increases by about 10% when the low-k dielectric is used as the gap fill. The critical current density for the low-k structures under pulsed condition is shown to be about 10-30% lower than that of standard dielectric structures depending on metal and pulse widths.