Analysis and Modeling of an 11.8 GHz Fin Resonant Body Transistor in a 14 nm FinFET CMOS Process

In this work, a compact model is presented for a 14-nm CMOS-based fin resonant body transistor (fRBT) operating at a frequency of 11.8 GHz and targeting radio frequency (RF) 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 displacement component coupling due to the periodic nature of the back-end-of-line (BEOL) metal phononic crystal (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 Berkeley short channel IGFET model (BSIM)-common multigate (CMG) 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 toward change in transduction mechanisms and device architecture. Ultimately, the behavior 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.