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AssigneeShin-Etsu Chemical Co., Ltd.
InventorsRyo Iwasaki, Noriaki Hamaya, Yugo Taniguchi
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According to the present invention, a yttrium-fluoride-based sprayed coating that has a Vickers hardness of 350 or higher, includes a YF3 crystal phase having an orthorhombic crystal system, and does not include a YF3 crystal phase having a crystal system other than an orthorhombic crystal system is produced by plasma-spraying a spray powder that includes a YF3 crystal phase having an orthorhombic crystal system and does not include a YF3 crystal phase having a crystal system other than an orthorhombic crystal system. In the present invention, it is possible to provide a yttrium-fluoride-based sprayed coating that has a high coating hardness and is such that the amount of particles generated upon exposure to a halogen-based gas plasma is low, and such a sprayed coating is exceptional as a sprayed coating formed on a member for a semiconductor-producing device that is used in a semiconductor production step.
An yttrium-fluoride-based sprayed coating comprising an orthorhombic YF3 crystal phase and a crystal phase of Y5O4F7, being free of a YF3 crystal phase other than an orthorhombic YF3 crystal phase, and having a mean crystallite size of 5 nm to 70 nm that is determined from half widths of diffraction peaks attributed to (101), (020), and (210) planes of the orthorhombic YF3 crystal phase by a Williamson-Hall method, and a Vickers hardness of 350 or more.
Dependencies are inferred from the claim text.