Modeling Capacitive Coupling Effects via the Substrate

For modern integrated circuits, capacitive coupling effects between interconnects can play an important role. Also resistive coupling effects via the substrate may have a significant influence on circuit behavior. This has already been recognized some time ago [1], and several methods to model these effects have been developed [2]. In this paper we will show how we can model coupling effects that propagate through capacitances as well as through substrate resistances. We will describe a 3 dimensional model that allows to accurately and efficiently model these effects. It extends work that has previously been reported in [3] and [4]. We will give results that indicate that in some cases capacitive coupling effects via the substrate may severely degenerate circuit performance. Keywords— Parasitic coupling effects, Interconnect modeling, Substrate modeling, Simulation, RF.