Impact of Linear Intergranular Variation in Remnant Polarization on Negative Capacitance Field Effect Transistor

We present an explicable study of the impact of variability in the remnant polarization (Pr) of the polycrystalline ferroelectric layer of a double gate (DG) NCFET. We analyze the impact of intergranular linear variance in Pr considering (i) source end as reference point and (ii) drain end as reference point with the percentage value advancing to the other end. The study evaluates the device performance at various ferroelectric thicknesses for both long as well as short gate lengths. The electrical characteristics exhibit different behaviour for low and high values of applied drain bias. While for low drain voltage, intuitive results are obtained, high drain voltage characteristics follow a distinct trend of subthreshold swing (SS) decreasing from its initially deteriorated value, as the magnitude of Pr variance decreases from source to drain, whereas the tendency is reversed moving from drain to source. Based on the results, we further conclude that in order to prevent the hysteric effects, the granular variation between the first and the last grain should not exceed 25% for long channel and 20% for short channel devices.