Abstract: An yttrium fluoride spray material contains Y5O4F7 and YF3, and has an average particle size of 10-60 ?m and a bulk density of 1.2-2.5 g/cm3. The Y5O4F7 and YF3 in the yttrium fluoride spray material consist of 30 to 90% by weight of Y5O4F7 and the balance of YF3. A sprayed coating of yttrium oxyfluoride is obtained by atmospheric plasma spraying of the spray material.

Abstract: An yttrium fluoride spray material contains Y5O4F7 and YF3, and has an average particle size of 10-60 ?m and a bulk density of 1.2-2.5 g/cm3. The Y5O4F7 and YF3 in the yttrium fluoride spray material consist of 30 to 90% by weight of Y5O4F7 and the balance of YF3. A sprayed coating of yttrium oxyfluoride is obtained by atmospheric plasma spraying of the spray material.

Abstract: An yttrium fluoride spray material contains YO5O4F7 and YF3, and has an average particle size of 10-60 ?m and a bulk density of 1.2-2.5 g/cm3. The Y5O4F7 and YF3 in the yttrium fluoride spray material consist of 30 to 90% by weight of Y5O4F7 and the balance of YF3. A sprayed coating of yttrium oxyfluoride is obtained by atmospheric plasma spraying of the spray material.

Abstract: A sprayed article is prepared by thermally spraying ceramic particles of rare earth oxide or fluoride or metal particles of W, Mo or Ta onto an outer or inner surface of a cylindrical carbon substrate to form a sprayed coating, and burning out the carbon substrate, thus leaving the ceramic or metal-base sprayed coating of cylindrical shape having a wall thickness of 0.5-5 mm.

Abstract: A sprayed article is prepared by thermally spraying ceramic particles of rare earth oxide or fluoride or metal particles of W, Mo or Ta onto an outer or inner surface of a cylindrical carbon substrate to form a sprayed coating, and burning out the carbon substrate, thus leaving the ceramic or metal-base sprayed coating of cylindrical shape having a wall thickness of 0.5-5 mm.

Abstract: An yttrium fluoride sprayed coating having a thickness of 10-500 ?m, an oxygen concentration of 1-6 wt %, and a hardness of 350-470 HV is deposited on a substrate surface. The yttrium fluoride sprayed coating exhibits excellent corrosion resistance in a halogen-base gas atmosphere or halogen-base gas plasma atmosphere, functions to protect the substrate from damage by acid penetration during acid cleaning, and minimizes particle generation from a reaction product and due to spall-off from the coating.

Abstract: An yttrium-base sprayed coating is obtained by thermally spraying yttrium oxide, yttrium fluoride or yttrium oxyfluoride onto a substrate to form a coating of 10-500 ?m thick, and chemically cleaning the coating with a cleaning liquid of organic acid, inorganic acid or a mixture thereof until the population of particles with a size of up to 300 nm becomes no more than 5 particles/mm2 of the coating surface. The yttrium-base sprayed coating exhibits high corrosion resistance even in a halogen gas plasma atmosphere and prevents yttrium-base particles from spalling off during etching treatment.

Abstract: An yttrium fluoride spray material contains Y5O4F7 and YF3, and has an average particle size of 10-60 ?m and a bulk density of 1.2-2.5 g/cm3. The Y5O4F7 and YF3 in the yttrium fluoride spray material consist of 30 to 90% by weight of Y5O4F7 and the balance of YF3. A sprayed coating of yttrium oxyfluoride is obtained by atmospheric plasma spraying of the spray material.

Abstract: An yttrium-base sprayed coating is obtained by thermally spraying yttrium oxide, yttrium fluoride or yttrium oxyfluoride onto a substrate to form a coating of 10-500 ?m thick, and chemically cleaning the coating with a cleaning liquid of organic acid, inorganic acid or a mixture thereof until the population of particles with a size of up to 300 nm becomes no more than 5 particles/mm2 of the coating surface. The yttrium-base sprayed coating exhibits high corrosion resistance even in a halogen gas plasma atmosphere and prevents yttrium-base particles from spalling off during etching treatment.

Abstract: A powder comprising rare earth element fluoride particles having an aspect ratio of up to 2, an average particle size of 10-100 ?m, a bulk density of 0.8-1.5 g/cm3, and a carbon content of 0.1-0.5 wt % is amenable to atmospheric plasma spraying. An article obtained by spraying the rare earth fluoride spray powder to a substrate undergoes few partial color changes and performs well even when used in a halogen gas plasma.

Abstract: A rare earth oxide-containing sprayed plate is prepared by thermally spraying a rare earth oxide on a support to a thickness of up to 5 mm and peeling the sprayed coating from the support. Thin plates of rare earth oxide ceramics can be prepared without molding, firing and sintering steps.

Abstract: A spray material comprising rare earth element oxyfluoride particles having an aspect ratio of up to 2, an average particle size of 10-100 ?m, and a bulk density of 0.8-2 g/cm3, and containing not more than 0.5 wt % of carbon and 3-15 wt % of oxygen is suitable for air plasma spraying. An article having a sprayed coating of rare earth element oxyfluoride has high resistance against plasma etching and a long lifetime.

Abstract: A powder comprising rare earth element fluoride particles having an aspect ratio of up to 2, an average particle size of 10-100 ?m, a bulk density of 0.8-1.5 g/cm3, and a carbon content of 0.1-0.5 wt % is amenable to atmospheric plasma spraying. An article obtained by spraying the rare earth fluoride spray powder to a substrate undergoes few partial color changes and performs well even when used in a halogen gas plasma.

Abstract: A sprayed article is prepared by thermally spraying ceramic particles of rare earth oxide or fluoride or metal particles of W, Mo or Ta onto an outer or inner surface of a cylindrical carbon substrate to form a sprayed coating, and burning out the carbon substrate, thus leaving the ceramic or metal-base sprayed coating of cylindrical shape having a wall thickness of 0.5-5 mm.

Abstract: A spray material comprising rare earth element oxyfluoride particles having an aspect ratio of up to 2, an average particle size of 10-100 ?m, and a bulk density of 0.8-2 g/cm3, and containing not more than 0.5 wt % of carbon and 3-15 wt % of oxygen is suitable for air plasma spraying. An article having a sprayed coating of rare earth element oxyfluoride has high resistance against plasma etching and a long lifetime.

Abstract: A wafer has a rare earth oxide layer disposed, typically sprayed, on a substrate. It is useful as a dummy wafer in a plasma etching or deposition system.

Abstract: A wafer has a rare earth oxide layer disposed, typically sprayed, on a substrate. It is useful as a dummy wafer in a plasma etching or deposition system.

Abstract: A wafer has a rare earth oxide layer disposed, typically sprayed, on a substrate. It is useful as a dummy wafer in a plasma etching or deposition system.

Abstract: A wafer has a rare earth fluoride coating disposed, typically sprayed on a substrate as an outermost layer, the rare earth fluoride being selected from lanthanoid fluorides, yttrium fluoride, and scandium fluoride. It is useful as a dummy wafer in a plasma etching or deposition system.

Abstract: A graphite-silicon carbide composite comprises a graphite substrate and a silicon carbide layer formed thereon and comprising silicon carbide particles in fused and contact bonded state. The composite has excellent oxidation resistance and finds a wide range of application as heat resistant material. The method of forming a silicon carbide layer on graphite surface is simple and consistent.