Impacts of low-k film on sub-100 nm-node, ULSI devices

By using an interconnect performance analysis model with the interconnect length distribution function, the effects of low-k film on ULSI device performances are estimated from 180 nm-node to 65 nm-node. Due to abrupt increment of the interconnect length in the 65 nm-node ULSIs, the total interconnect parasitic capacitance becomes dominant relative to the total transistor capacitance on the chip. Therefore, the introduction of low-k materials provides a great impact on lowering the interconnect parasitic capacitance, or essentially the chip power consumption. The ULSI chip performance such as "low-power and multi-functionality" is estimated to achieve 46% valued-up by replacement of the conventional SiO₂ by a porous low-k film with the effective dielectric constant of k_eff=2.5. The introduction of porous low-k films is cruical for the 65 nm-node ULSIs.