Toward Energy-Efficient Ferroelectric Field-Effect Transistors and Ferroelectric Random Access Memories: Tailoring the Coercive Field of Ferroelectric HfO2 Films

Abstract

Many modern applications require fast and reliable nonvolatile memory. Ferroelectric (FE) memories, such as FE field-effect transistors and FE random access memories, show great promise in meeting these requirements. Another key factor is power efficiency. In the case of FE memories, the coercive field (Formula presented.) is a critical parameter for improving power consumption. This article introduces and reviews four promising methods to tailor the (Formula presented.) of FE films based on Zr-doped (Formula presented.) : 1) (Formula presented.) composites with various Hf contents, 2) hybrid stacks consisting of antiferroelectric (Formula presented.) sublayers with excess Zr (x (Formula presented.) 0.5) and FE (Formula presented.) sublayers, 3) superlattice structures (also known as nanolaminates) consisting of (Formula presented.) and (Formula presented.) sublayers stacked on top of each other, and 4) (Formula presented.) films doped with an aluminum impurities. Electrical characterization of metal–FE–metal capacitor test structures confirms the suitability of all approaches. Analysis of the strengths and weaknesses is conducted, considering the tuning range, shape stability of the polarization versus electric field hysteresis loop, and the impact of these approaches on the remanent polarization (Formula presented.).