Negative-Capacitance Characteristics in a Steady-State Ferroelectric Capacitor Made of Parallel Domains

In this letter, the negative-capacitance characteristics in a steady-state ferroelectric capacitor made of parallel domains are investigated by modeling. Through simulation and analysis of dynamic process, we demonstrate that the ferroelectric capacitor in steady states can hold one negative-capacitance domain at most. As a result, the manifested charge-voltage curve for the multi-domain ferroelectric is remarkably different from the S-shaped curve for single-domain ferroelectric. The conclusion can be readily generalized to parallel negative-capacitance capacitors. It indicates that dynamic process of polarization evolving in time domain plays critical roles in analyzing negative-capacitance characteristics even for steady-state ferroelectric devices. Significant ingredients are revealed for understanding and exploring negative-capacitance devices.