Composition, microstructure, and mechanical properties of Y2O3 films in post-deposition annealing

A series of Y2O3 films was prepared through reactive magnetron sputtering and further annealed at 350 °C and 500 °C. Differential scanning calorimetry reveals that the physisorbed oxygen (Oδ) of the as-deposited films was desorbed to O2 (g) from 268.8 to 336.5 °C, and the desorption quantity of Oδ was 22.6%. Grazing incidence X-ray diffraction results showed that the films remained at a cubic phase (111) out-of-plane in all annealing states. Microphotographs revealed that the as-deposited films and the films annealed at 350 °C contained a regular columnar structural grain which almost disappeared in the films annealed at 500 °C. The Y2O3 films annealed at 350 °C exhibited excellent mechanical properties, elastic modulus (EIT) of 280 GPa, and hardness (HIT) of 12 GPa.