Investigation of fluoride layer of yttria coatings prepared by aerosol deposition method

Abstract

The fluorination of Yttria (Y2O3) coatings in the inner chamber wall of a plasma-etching equipment causes a process drift. In this paper, we investigate the relationship between the microstructure and fluoride layer of Y2O3 coatings prepared by aerosol deposition (AD) method compared with Y2O3 coatings prepared by atmospheric plasma spraying (APS) and ion plating (IP). The plasma corrosion of AD-coating, which has a highly dense microstructure without any pores, proceeded homogeneously and the specific surface area maintained its initial smooth surface. Moreover, F atoms slightly penetrated the AD-coating and formed a very thin, 45-nm fluoride layer after plasma exposure. The total area of the surface fluoride layer did not increase with plasma exposure time because the surface remained smooth. Therefore, Y2O3 coating prepared by AD can suppress surface fluorination and process drift compared with Y2O3 coatings prepared by APS and IP.