Characterization of Dynamic Substrate Macro-Model in Mixed Signal IC Systems Using 3-D Finite Element Method

In the modern mixed-signal IC design, accurate substrate model is important for substrate noise analysis and analog circuit simulation. As the operation frequency increases and the high-resistivity substrate is used, the capacitive effect in substrate becomes important and the substrate impedances become frequency dependent. The dynamic behavior of the substrate needs to be considered. In this paper, the characterization of dynamic substrate macro-model in mixed-signal IC systems using a 3-D finite element based dynamic RC field solver is presented. The dynamic behavior of substrate macro-model is studied on two traditional heavily-doped and lightly-doped substrates and the noise isolation method such as the use of guard rings is also considered.