  In this work, a compact model is presented for a 14 nm CMOS-based FinFET
Resonant Body Transistor (fRBT) operating at a frequency of 11.8 GHz and
targeting RF frequency generation/filtering for next generation radio
communication, clocking, and sensing applications. Analysis of the phononic
dispersion characteristics of the device, which informs the model development,
shows the presence of polarization exchange due to the periodic nature of the
back-end-of-line (BEOL) metal PnC. An eigenfrequency-based extraction process,
applicable to resonators based on electrostatic force transduction, has been
used to model the resonance cavity. Augmented forms of the BSIM-CMG (Common
Multi-Gate) model for FinFETs are used to model the drive and sense transistors
in the fRBT. This model framework allows easy integration with the
foundry-supplied process design kits (PDKs) and circuit simulators while being
flexible towards change in transduction mechanisms and device architecture.
Ultimately, the behaviour is validated against RF measured data for the
fabricated fRBT device under different operating conditions, leading to the
demonstration of the first complete model for this class of resonant device
integrated seamlessly in the CMOS stack.
