Tailoring of the coercive voltage in a ferroelectric polymer capacitor

Abstract

For an identical ferroelectric material, operation at a different voltage means that all ferroelectric films should be designed for different thicknesses, though this increases the degree of process complexity. Here, a technique which can be used to adjust the coercive voltage (VC) of a metal-ferroelectric film-metal capacitor is demonstrated. The VC-adjustable capacitor was fabricated with ferroelectric polymer film and the capacitor consists of two sub-capacitors with different thicknesses. For a common top and bottom electrode, the sub-capacitors are equivalent to two parallel-connected capacitors. With regard to the variance of the ratio of the area of the sub-capacitors, a VC-adjustable capacitor can take coercive voltage between two VC values, each of which correspond to the VC value of each respective sub-capacitor. In this demonstration, the width of the tuning range of the VC values was 3.6V. In addition, the strategy for a linear VC adjustment of a VC-adjustable capacitor is discussed in terms of the concept of nonlinearity. This demonstration with a ferroelectric polymer is predicted to be applicable to emerging organic electronic applications.