Inter-grain Interactions in Polycrystalline Hafnium-Zirconium-Oxide Ferroelectrics

Ferroelectric (FE) Hafnium-Zirconium-Oxide (HZO) has shown promise for emerging applications due to its CMOS compatibility and scale-free ferroelectricity [1, 2]. However, the polycrystallinity of HZO poses several concerns related to device-to-device variability [2–5]. Addressing this problem requires modeling and understanding polycrystalline effects on FE device performance. Several models capture the polarization switching in polycrystalline FE [3–7], differing in their treatment of polycrystalline grains and inter-grain interactions (Fig. 2a). These approaches range from considering independent grains to fully coupled grains via electrostatics, polarization gradient, and strain. This work theoretically investigates inter-grain electrostatic and polarization-gradient interactions in polycrystalline FE, highlighting their effects on device characteristics and polarization switching.