Nanoscale Ferroelectrics in High-Frequency Devices: ab Initio Modeling and Multiscale Approach

In this paper, we investigate novel multi-physics simulations in both time and frequency domains to enable predictive modeling of nanoscale ferroelectric devices for highfrequency applications. Our approach addresses polarization dynamics in sub- 10 nm hafnium-based ferroelectric films in the GHz range. We examine the ferroelectric material response up to 40 GHz under 30 dBm input power and assess conductor losses, including skin depth limitations and charge redistribution near the ferroelectric interface. The Density Functional Theory (DFT) approach has been used to gain insights into the interface phenomena of MIM diodes, demonstrating how advanced computational tools can predict the performance of nanoscale devices and guide fabrication choices. In particular, two different MIM diodes based on the orthorhombic Pca2<inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">1</inf> phases of HfO<inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</inf> were examined. Since it is well known that o-HfO<inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</inf> exhibits intrinsic ferroelectric behavior, the MIM diodes were built to have spontaneous polarization toward the drain or the source electrode.