Hafnium Oxide-Based Ferroelectric Devices for In-Memory Computing: Resistive and Capacitive Approaches

Abstract

The integration of ferroelectric hafnium oxide (HfO 2 ) into semiconductor device structures has been a breakthrough in the development of state-of-the-art in-memory computing (IMC) technology. The high compatibility of ferroelectric HfO 2 with backend-of-the-line (BEOL) as well as conventional complementary metal-oxide-semiconductor (CMOS) process technologies enables the development of highly efficient embedded IMC applications. In this work, we consider both resistive and capacitive approaches to the realization of IMC-compatible devices using ferroelectric HfO 2 . Process optimization and device integration concepts based on ferroelectric HfO 2 are presented in this context. This Spotlight on Applications also reviews the reliability and reproducibility of HfO 2 -based ferroelectric devices. IMC architectures involving resistive systems are well established and mature. We discuss the capabilities and remarkable progress toward the integration of memristive ferroelectric HfO 2 devices in these IMC architectures. Special attention is also given to the recently emerged ferroelectric capacitor (Fe-Cap)-based memcapacitive systems, which offer low-power consumption based on their open-circuit nature. Distinguished by their nondestructive readout capability, Fe-Caps stand out from other capacitive memories that require switching memory states and refresh cycles during access operations. Finally, we compare the electrical performance of Fe-Cap devices with other memristive technologies for IMC applications. This provides insights into the potential of ferroelectric HfO 2 -based devices for the development of highly efficient and advanced IMC systems.