Low-thermal-budget (300 degrees C) ferroelectric TiN/Hf0.5Zr0.5O2/TiN capacitors realized using high-pressure annealing

In this Letter, a high-pressure annealing (HPA) process is proposed as a way to reduce the thermal budget of Hf0.5Zr0.5O2 (HZO) thin films with ferroelectric behaviors. The low-thermal-budget process is essential for integrating ferroelectric devices in the back-end-of-line to provide more functionalities and effective memory area. For the HZO film annealed at 300 & DEG;C using the HPA process, an orthorhombic phase responsible for ferroelectric behavior was formed with a decrease in film thickness, resulting in a remanent polarization (P-r) of & SIM;13 mu C/cm(2) (i.e., 2P(r) of & SIM;26 mu C/cm(2)). Meanwhile, when only the annealing time was increased at 300 & DEG;C without applying pressure, the HZO film did not crystallize and exhibited linear dielectric properties. Consequently, the HZO films (< 10 nm) can be crystallized by applying pressure (15 atm) even at low temperatures of 300 & DEG;C, thereby obtaining ferroelectric properties.