A coating material containing an oxyfluoride of yttrium and having a Fisher diameter of 1.0 to 10 μm and a tap density TD to apparent density AD ratio, TD/AD, of 1.6 to 3.5. The coating material preferably has a pore volume of pores with a diameter of 100 μm or smaller of 1.0 cm.sup.3/g or less as measured by mercury intrusion porosimetry. A coating containing an oxyfluoride of yttrium and having a Vickers hardness of 200 HV0.01 or higher. The coating preferably has a fracture toughness of 1.0×10.sup.2 Pa.Math.m.sup.1/2 or higher.

A coating material containing an oxyfluoride of yttrium and having a Fisher diameter of 1.0 to 10 μm and a tap density TD to apparent density AD ratio, TD/AD, of 1.6 to 3.5. The coating material preferably has a pore volume of pores with a diameter of 100 μm or smaller of 1.0 cm.sup.3/g or less as measured by mercury intrusion porosimetry. A coating containing an oxyfluoride of yttrium and having a Vickers hardness of 200 HV0.01 or higher. The coating preferably has a fracture toughness of 1.0×10.sup.2 Pa.Math.m.sup.1/2 or higher.

A plasma processing device member according to the disclosure includes a base material and a film formed of a rare-earth element oxide, or a rare-earth element fluoride, or a rare-earth element oxyfluoride, or a rare-earth element nitride, the film being disposed on at least part of the base material. The film includes a surface to be exposed to plasma, the surface having an arithmetic mean roughness Ra of 0.01 μm or more and 0.1 μm or less, the surface being provided with a plurality of pores, and a value obtained by subtracting an average equivalent circle diameter of the pores from an average distance between centroids of adjacent pores is 28 μm or more and 48 μm or less. A plasma processing device according to the disclosure includes the plasma processing device member described above.

A plasma processing device member according to the disclosure includes a base material and a film formed of a rare-earth element oxide, or a rare-earth element fluoride, or a rare-earth element oxyfluoride, or a rare-earth element nitride, the film being disposed on at least part of the base material. The film includes a surface to be exposed to plasma, the surface having an arithmetic mean roughness Ra of 0.01 μm or more and 0.1 μm or less, the surface being provided with a plurality of pores, and a value obtained by subtracting an average equivalent circle diameter of the pores from an average distance between centroids of adjacent pores is 28 μm or more and 48 μm or less. A plasma processing device according to the disclosure includes the plasma processing device member described above.

Provided are a member for plasma processing device which has an excellent plasma resistance and improved adhesion strength of a film to a base material, and a plasma processing device provided with the same. A member for plasma processing device includes: a base material containing a first element which is a metal element or a metalloid element; a film containing a rare-earth element oxide, or a rare-earth element fluoride, or a rare-earth element oxyfluoride as a major constituent, the film being located on the base material; and an amorphous portion containing the first element, a rare earth element, and at least one of oxygen and fluorine, the amorphous portion being interposed between the base material and the film.

Provided are a member for plasma processing device which has an excellent plasma resistance and improved adhesion strength of a film to a base material, and a plasma processing device provided with the same. A member for plasma processing device includes: a base material containing a first element which is a metal element or a metalloid element; a film containing a rare-earth element oxide, or a rare-earth element fluoride, or a rare-earth element oxyfluoride as a major constituent, the film being located on the base material; and an amorphous portion containing the first element, a rare earth element, and at least one of oxygen and fluorine, the amorphous portion being interposed between the base material and the film.

The present invention provides a plasma-resistant ceramic member, which includes a substrate and a ceramic coating layer formed on the substrate, in which the ceramic coating layer includes a lower layer consisting of an oxide formed on the substrate, and a surface layer in which an oxide composition component constituting the surface of the ceramic coating layer is surface-modified with a composition containing one or more anions selected from the group consisting of F.sup.− and Cl.sup.−, wherein the surface layer is a layer in which a raw material containing one or more anions selected from the group consisting of F.sup.− and Cl.sup.− is vaporized by heating and adsorbed to the surface of the ceramic coating layer, and thus modified with a composition containing one or more anions selected from the group consisting of F.sup.− and Cl.sup.−, and a method of manufacturing the same. According to the present invention, the plasma-resistant property, durability, and etching process stability of the ceramic member may be improved with low costs.

A plasma processing device member according to the disclosure includes a base material and a film formed of an oxide, or fluoride, or oxyfluoride, or nitride of a rare-earth element, the film being disposed on at least part of the base material, the film including a surface to be exposed to plasma, the surface having an area occupancy of open pores of 8% by area or more, and an average diameter of open pores of 8 μm or less.

A plasma processing device member according to the disclosure includes a base material and a film formed of an oxide, or fluoride, or oxyfluoride, or nitride of a rare-earth element, the film being disposed on at least part of the base material, the film including a surface to be exposed to plasma, the surface having an area occupancy of open pores of 8% by area or more, and an average diameter of open pores of 8 μm or less.

A coating material containing an oxyfluoride of yttrium and having a Fisher diameter of 1.0 to 10 μm and a tap density TD to apparent density AD ratio, TD/AD, of 1.6 to 3.5. The coating material preferably has a pore volume of pores with a diameter of 100 μm or smaller of 1.0 cm.sup.3/g or less as measured by mercury intrusion porosimetry. A coating containing an oxyfluoride of yttrium and having a Vickers hardness of 200 HV0.01 or higher. The coating preferably has a fracture toughness of 1.0×10.sup.2 Pa.Math.m.sup.1/2 or higher.