Modeling of SOI-MOS capacitors C-V behavior: partially- and fully-depleted cases

A model is presented for the C-V characteristics of partially-depleted (PD) and fully-depleted (FD) SOI-MOS capacitors. The proposed model is flexible, allowing introduction of all types of nonidealities typical to MOS type structures. New formulae for the low- and high-frequency capacitances of these structures are derived. Due to the various charges stored in these structures, unusual and more complex C-V curves are obtained. C-V curves where interface-state densities have been individually introduced (one at a time) at all three SiO₂-Si interfaces of the SOI-MOS-C are also demonstrated. The model has been validated by fitting the predicted HF C-V curves for SOI-MOS-C and its inherent structure, the SIS capacitor, to the experimental data. The extracted electrophysical parameters of the studied structures, for both PD and FD cases, are very close, if not the same as the values determined during their fabrication