Impact of Process Variations on Negative Capacitance FinFET Devices and Circuits

We report on the impact of process variations on short-channel negative capacitance (NC)-based FinFETs through statistical Monte Carlo simulations using a physics-based model of NC-FinFETs. We find that relative to regular FinFETs, the impact of geometrical variability can be lesser or higher in NC-FinFETs in different regimes of device operation and is strongly dependent on the nominal ferroelectric (FE) thickness (t(fe)). The contribution of the FE layer to the overall variability behaves non-monotonically with increase in the nominal tfe. While the OFF-current and threshold voltage variabilities scale down, the ON-current variability does not follow a monotonic trend with increase in the nominal t(fe). We also show that although relative to the regular FinFET-based ring oscillator (RO) circuit, the NC-FinFET-based RO (NC-RO) circuit displays increased immunity to process variation induced delay variability, the trend is non-monotonic with regard to tfe scaling.