Effect of High Pressure Annealing Temperature on the Ferroelectric Properties of TiN/Hf0.25Zr0.75O2/TiN Capacitors

In recent years, hafnium zirconium oxide (HZO) has received significant attention of the research community due to the demontsrattion of ferroelectricity at sub 10 nm thickness and good CMOS-compatibility. However, ferroelectricity in HZO is dependent on various factors such as the HZO composition, materials used as top or bottom electrode, post metallization technique, annealing pressure and temperature etc. Herein, we have systematically investigated the effect of high pressure post metallization annealing (HPPMA) temperature on the ferroelectric properties of TiN/Hf0.25Zr0.75O2/TiN capacitors. Hf0.25Zr0.75O2, that show antiferroelectric behavior in rapid thermal annealing, demonstrate antiferroelectric to ferroelectric phase transition depending on the HPPMA temperature. Maximum remanent polarization (Pr) of ~29μC/cm² is achieved for HPPMA temperature 550 °C whereas the maximum dielectric constant (k) of ~46 is achieved for HPPMA temperature 350 °C. The interfacial capacitance of the MFM capacitors increased with increasing the HPPMA annealing temperature. The results obtained in this study open up the possibility of achieving high-k ferroelectric capacitors using Zr rich HZO films that can be applicable to various electronic devices.