Dielectric Loss Effects on the Modeling of Interconnect Responses for the 45 nm Node

Recent complex permittivity measurements of low-k porous SiOCH have outlined that dielectric losses cannot be considered negligible. Furthermore those results show apparently non causal dependence of real and imaginary parts of the permittivity with frequency. This behaviour leads to inconsistent models of interconnects, as illustrated in this paper regarding the 45 nm technology node. Time domain simulations using such models induce errors, especially on the propagation delay. To give a factual vision of this purpose, two different dielectric loss models have been studied to prove the requirement of the greatest care to evaluate interconnect responses.