Ground-Semiconductor-Ground Guiding Phenomena of Noise Coupling in CMOS Substrate

Ground-semiconductor-ground (GSG) transmission line (TL) is proposed and investigated thoroughly for the assessment of CMOS signal integrity problem at multi-GHz frequency regime. The GSG TL models the practical implementation of CMOS logic layout, which consists of power line, Nwell line (semiconductor), Pwell line (semiconductor), and ground line. Rigorous field-theory analyses and experiments show that GSG TL supports the CPW (coplanar waveguide) mode for the particular case study, which also demonstrate the slow-wave factor can be as high as 50 at 1 GHz and decrease to 10 at 10 GHz, pointing to the fact that the slow-wave phenomena will be more pronounced for CMOS electronics operated beyond tens of GHz