Phases in HfO2-Based Ferroelectric Thin Films and Their Integration in Low-Power Devices

Abstract

HfO2-based ferroelectrics are applied in a large spectrum of electronic devices ranging from ultralow-power logic to nonvolatile memory. The efficacy of these ferroelectrics is that these offer complementary metal oxide semiconductor compatibility in conjunction with large coercive fields and ferroelectricity at sub-10 nm thicknesses. Because of these advantages compared with conventional lead-based thick perovskite films (>50 nm), the present spotlight article focuses on their use to surpass the physical limit of the subthreshold swing (60 mV/dec at room temperature) of field-effect transistors (FETs) via the stabilization of the negative capacitance. In addition, the discussion on HfO2-ferroelectric-based memories is focused on two-terminal random-access devices, tunnel junctions, three-terminal ferroelectric FETs and their respective 3D stacked architectures.