Effects of HfO2 addition on the plasma resistance of Y2O3 thin films deposited by e-beam PVD

Ceramic Y2O3 thin films are often used to coat the inner walls of etching equipment during semiconductor manufacturing to protect them from bombardment by high-energy plasma ions, which can degrade the equipment and cause semiconductor contamination. In this study, the effects of HfO2 addition to the Y2O3 thin film on the plasma resistance were investigated. Thin films were fabricated using electron beam-physical vapor deposition. The addition of HfO2 maintained the cubic Y2O3 crystalline structure while substantially improving the etch resistance during fluorine-based plasma etching. X-ray photoelectron spectroscopy analysis of the etched surface showed that HfO2 addition resulted in a lower F/(O + F) ratio, thus promoting the formation of more Y–O bonds that are more resistant to physical sputtering. Additionally, the analysis indicated that Hf4+ was more likely to be removed from the etched surface than Hfx+ (x < 4). This novel strategy is expected to aid in the development of improved plasma-resistant ceramic materials.