A Monte Carlo TCAD simulation study of the impact of polycrystallinity and dielectric phases of the ferroelectric film on an 8/7 nm node NC-FinFET is presented. The study considers the random variation of ferroelectric remnant polarization ( P r) and the presence of dielectric phases. In order to keep the ferroelectric-film induced device variability less than those induced by other sources (RDF, GER, FER, and MGG), we found that the DE content must be less than 20%, which is theoretically possible, and the grain to grain P r variations less than 27%. While uniform single-crystalline ferroelectric film would provide the least device variation, we found 4 nm grains to produce less device variability than 5.3 nm grains due to the larger number of grains in the channel area. © 2018 IEEE.