Dead layer thickness estimation at the ferroelectric film-metal interface in PZT

Abstract

Different models for estimation of the dead layer thickness at the ferroelectric film-metal interface are discussed, including the small-signal capacitance model and two methods based on dielectric hysteresis analysis—one based on slopes of the hysteresis loops at the coercive field and the other method based on comparison of dielectric hysteresis portraits. It is shown that the latter technique yields more reliable data as it excludes the effect of leakage and relaxation loss. Conductivity may have a pronounced effect on the validity of dead-layer thickness data. This work relates peripherally to negative capacitance in ferroelectric films and to lozenge-shaped hysteresis curves.