Advances in the APS deposition of Yttrium Oxide and Yttrium Oxyfluoride

Yttrium oxide has been shown to be a highly plasma-resistant material for the coating of etch chambers used in semiconductor processing facilities. During exposure to the fluorine containing etching gases, these coatings suffer from chemical attack and modification of the surface of the coating which leads to the eventual degradation of the coating in the form of erosion and particle generation. Yttrium oxyfluoride has been proposed as a promising alternate material due to its resistance to fluorine infiltration into the bulk of the coating. Unfortunately, most efforts to fabricate yttrium oxyfluoride coatings by air plasma spray (APS) result in severe degradation and decomposition of the oxyfluoride starting chemistry. The result is coatings with highly oxidized yttrium oxyfluoride and fully oxidized forms of yttria that render the change in coating chemistry of the feedstock ineffective. In this talk, advances made in deposition technology at Praxair Surface Technologies to significantly improve coating chemistries of yttrium oxyfluoride will be presented.