In this letter, we have investigated the RF performance of a negative capacitance FinFET (NC-FinFET) using BSIM-CMG compact model extracted from DC and RF measured data of 10-nm technology node devices. This physics-based RF model is then coupled self-consistently with the Landau-Khalatnikov equation to obtain the RF NC-FinFET model. For the first time, we report, here, the impact of ferroelectric thickness (tfe) scaling on RF performance of NC-FinFET and find that NC-FinFET's cutoff frequency (fT) is a function of tfe. We also observe that the self-heating effect in NC-FinFET increases with increase in tfe, mainly due to increase in DC current, which can be easily compensated by decreasing supply voltage. Finally, we show that NC-FinFET can achieve similar analog/RF performance as the base FinFET, even at a reduced VDD.