Many people do not realize that PISCES can be used for metal RC delay calculations. AC/capacitance analysis is possible, even when there is no conduction current (e.g., when the structure is just metal lines in oxide). Theoretically, all we really need to solve is Poisson's equation, although PISCES still forces you to do a 2-carrier solution for capacitance calculations.

SUPREM4 can be used to create realistic cross-sections (e.g., sloped metal sidewalls, multiple dielectrics). A cross section of such a device is shown below. We used the 2D RC values from SUPREM4/PISCES to perform a pseudo-3D analysis in Line Length Dependencies in Interconnect Optimization (D.Kadosh, M.Duane, Y.Lee) presented at SPIE Microelectronic Manufacturing, Oct 1, 1997.

See Q&A on this at the FAQ