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 24mu C/cm² 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.