Perspective of negative capacitance FinFETs investigated by transient TCAD simulation

Stability and instability of the negative capacitance (NC) states in metal (M) / ferroelectric (F) /M /insulator (I) /semiconductor (S) structures are rigorously studied using a newly developed transient TCAD simulation, in which time-dependent Landau-Khalatnikov (LK) equation can be considered. Our transient analysis reveals that NC becomes unstable due to formation of the inversion layer and gives rise to hysteresis in the NC-state, which cannot be simulated by the steady simulation. We propose a novel FinFET, in which the F-layer is located at the gate contact holes and exhibit a design guideline to avoid the instability of the NC-state using experimentally obtained ferroelectric parameters for (Hf, Zr)O2.