Improved Ferroelectric Switching in Sputtered HfZrO x Device Enabled by High Pressure Annealing

HfZrO _x (HZO) materials exhibiting ferroelectricity in ultra-thin layers can be deposited in various ways. Specifically, in sputtered HZO layers, only weak ferroelectric switching with gradual transition and small remnant polarization ( $\text {P}_{\text {r}}$ ) is demonstrated using conventional rapid thermal annealing at high temperatures of at least 750 °C. Here we show that rapidly transited ferroelectric switching with a larger 2 P _r of $24~\mu $ C/cm ² is achieved by introducing a high pressure annealing (HPA) at even lower temperature of 550 °C. Our findings reveal that the HPA enhances the crystallinity of grains in the HZO, thereby enlarging the P _r and strengthening breakdown conditions. Through short pulse techniques, how interface and bulk region in the HZO are involved in the switching depending on the HPA is also investigated.