Investigation of the interactions of NF3-based plasma with Y2O3 and YF3 coatings: Focus on contamination particle generation and wall redeposition

This study investigates the interactions of Y₂O₃ and YF₃ atmospheric plasma spraying (APS) coatings with NF₃/Ar/O₂ plasma, focusing on their positions on chamber electrodes and walls. The electrode coatings showed mass loss due to ion bombardment, with YF₃ experiencing more loss than Y₂O₃. Coatings on the walls gained mass from byproduct redeposition, with Y₂O₃ showing greater mass increase than YF₃ due to its higher fluorine reactivity, which enhanced F radical absorption and promoted redeposition. Scanning electron microscopy, energy dispersive X-ray spectroscopy, and X-ray photoelectron spectroscopy revealed that fine particles on the coatings either agglomerated or were removed, with agglomerated particles exhibiting high fluorine intensity. The results emphasize the importance of selecting the appropriate material based on its position in the chamber, as this significantly affects contamination and redeposition behaviors. These findings are crucial for optimizing material selection in plasma applications, improving process stability and equipment lifespan.