Comparison of Erosion Behavior and Particle Contamination in Mass-Production CF 4 /O 2 Plasma Chambers Using Y 2 O 3 and YF 3 Protective Coatings

摘要

Yttrium fluoride (YF 3 ) and yttrium oxide (Y 2 O 3 ) protective coatings prepared using an atmospheric plasma spraying technique were used to investigate the relationship between surface erosion behaviors and their nanoparticle generation under high-density plasma (10 12 –10 13 cm ?3 ) etching. As examined by transmission electron microscopy, the Y 2 O 3 and YF 3 coatings become oxyfluorinated after exposure to the plasma, wherein the yttrium oxyfluoride film formation was observed on the surface with a thickness of 5.2 and 6.8 nm, respectively. The difference in the oxyfluorination of Y 2 O 3 and YF 3 coatings could be attributed to Y–F and Y–O bonding energies. X-ray photoelectron spectroscopy analyses revealed that a strongly fluorinated bonding (Y–F bond) was obtained on the etched surface of the YF 3 coating. Scanning electron microscopy and energy dispersive X-ray diffraction analysis revealed that the nanoparticles on the 12-inch wafer are composed of etchant gases and Y 2 O 3 . These results indicate that the YF 3 coating is a more erosion-resistant material, resulting in fewer contamination particles compared with the Y 2 O 3 coating.