Plasma Etching Behavior of Atmospheric Plasma Sprayed Yttrium-based Coatings under NF3 Plasma

The interior coatings of semiconductor processing chambers exposed to plasma over a long period are subject to chemical and physical damage. In recent days, many studies have focused on fluorine-saturated yttrium-based coatings to obtain better material performance. In this study, yttrium oxide (Y₂O₃) and yttrium oxyfluoride (YOF) powders were synthesized and coated on an aluminum (Al) substrate using the atmospheric plasma spraying (APS) technique at different plasma powers of 25.6, and 25.2, 33.2 kW, respectively. Microstructure, macroscopic property, and chemical stability of dense Y₂O₃ and YOF-coated samples were analyzed. The plasma etching behavior of the Y₂O₃ and YOF coatings was investigated using PECVD- NF₃ plasma. The fluorination on the surface of coating materials was confirmed by X-ray photoelectron spectrum analysis (XPS). The relative intensity ratios of the Y–F to Y–O peaks on the Y₂O₃ and YOF coatings after exposure to NF₃ plasma were 1.30 and 1.48, respectively. These results indicate that the NF₃ plasma treated YOF film is more erosion resistant than the Y₂O₃ coating, and thus accumulates fewer contamination particles. Overall, YOF-coated samples are highly recommended for applications in the semiconductor industry due to better chemical stability with strong erosion resistance properties.