This paper investigates the effect of process variations on unity gain frequency (ft) in 30 nm gate length FinFET by performing extensive 3D TCAD simulations. TCAD tools are used to study device sensitivities on process variations. Sensitivity of ft on five different process parameters is studied. It is found that ft is more sensitive to gate length, underlap and corner radius, and less sensitive to hardmask height. Sensitivity of ft to fin width depends upon channel doping levels. © 2011 Springer-Verlag Berlin Heidelberg.