Multilevel approach for the investigation of substrate parasitics in mixed-signal IC's from full-wave analysis

This paper presents an original Multilevel approach of Substrate Parasitics in Mixed-Signal IC's from full-wave analysis based on a Transverse Waves Formulation. The concept of layout "approximation" is introduced to analyse the effects of "details" at different scales on the global coupling between pads. Realistic examples of typical BiCMOS structures are presented and results obtained by a home-made EM simulator are successfully compared to published measurements and to those of Moment Method approaches (SONNET Software). An original patterned grounded shield is proposed and demonstrates high isolation capability in presence of buried epitaxial layers.