Efficient polysilicon passivation layer for crosstalk reduction in high-resistivity SOI substrates

Substrate crosstalk and RF losses in HR-SOI, and the introduction of a stabilized polysilicon layer are deeply investigated. A new equivalent lumped circuit to model different substrate types and resistivities, and SiO₂-Si interface qualities is proposed and validated by simulation and experimental data. It is also valid to model the introduction of high-trap density at the interface, and it successfully explains the higher measured values of substrate crosstalk at low frequencies for HR-Si substrates.