Described herein is a protective coating composition that provides erosion and corrosion resistance to a coated article (such as a chamber component) upon the article's exposure to harsh chemical environment (such as hydrogen based and/or halogen based environment) and/or upon the article's exposure to high energy plasma. Also described herein is a method of coating an article with the protective coating using electronic beam ion assisted deposition, physical vapor deposition, or plasma spray. Also described herein is a method of processing wafer, which method exhibits, on average, less than about 5 yttrium based particle defects per wafer.

Described herein is a protective coating composition that provides erosion and corrosion resistance to a coated article (such as a chamber component) upon the article's exposure to harsh chemical environment (such as hydrogen based and/or halogen based environment) and/or upon the article's exposure to high energy plasma. Also described herein is a method of coating an article with the protective coating using electronic beam ion assisted deposition, physical vapor deposition, or plasma spray. Also described herein is a method of processing wafer, which method exhibits, on average, less than about 5 yttrium based particle defects per wafer.

An yttrium oxide-based sintered body contains yttrium oxide as a main constituent and 0.1 wt % or more and 5.0 wt % or less of zirconium on a ZrO.sub.2 basis. Such an yttrium oxide-based sintered body made with yttrium oxide and a certain amount of zirconium oxide therein is highly resistant to corrosive chemicals while maintaining superior resistance to plasma and corrosive gases.

An yttrium oxide-based sintered body contains yttrium oxide as a main constituent and 0.1 wt % or more and 5.0 wt % or less of zirconium on a ZrO.sub.2 basis. Such an yttrium oxide-based sintered body made with yttrium oxide and a certain amount of zirconium oxide therein is highly resistant to corrosive chemicals while maintaining superior resistance to plasma and corrosive gases.

A method for forming a transparent ceramic, in accordance with one embodiment, includes forming a green body by material jetting an ink, and processing the green body to form the ceramic to transparency. A product, in accordance with one embodiment, includes an ink for forming a transparent ceramic. The ink is physically characterized as having a density, surface tension, and viscosity configured to enable material jetting of the ink in contained, sequential droplets having a volume in the range of about 1 picoliter to about 1 nanoliter when jetted from a nozzle having an inner diameter in the range of about 10 microns to about 300 microns. A product, in accordance with another embodiment, includes a transparent ceramic, at least a portion of the transparent ceramic having layers of less than 50 microns per layer with physical characteristics of formation by material jetting.

According to an aspect of the invention, there is provided a plasma-resistant member including: a base member; and a layer structural component formed at a surface of the base member, the layer structural component including an yttria polycrystalline body and being plasma resistant, the layer structural component including a first uneven structure, and a second uneven structure formed to be superimposed onto the first uneven structure, the second uneven structure having an unevenness finer than an unevenness of the first uneven structure.

According to an aspect of the invention, there is provided a plasma-resistant member including: a base member; and a layer structural component formed at a surface of the base member, the layer structural component including an yttria polycrystalline body and being plasma resistant, the layer structural component including a first uneven structure, and a second uneven structure formed to be superimposed onto the first uneven structure, the second uneven structure having an unevenness finer than an unevenness of the first uneven structure.

This thermal spray material including composite particles containing an yttrium oxide and an ammonium yttrium fluoride complex salt is used to form a thermal spray film comprising yttrium oxyfluoride formed by thermal-spraying in the air. When the thermal spray film is formed through thermal-spraying in the air by using the thermal spray material of the present invention, the loss of fluorine from the thermal spraying material during thermal-spraying is reduced, and a thermal spray film containing yttrium oxyfluoride can be formed by controlling a composition, so that a thermal spray film having a desired composition, particularly a desired F/Y, can be easily formed.

A metering device (10) for withdrawing and dispensing a melt consisting of or containing an oxide fibre reinforced oxide ceramic composite material.

An air-permeable member of the present disclosure includes a porous ceramic having a columnar or plate shape. A root mean square slope RΔq in a roughness curve of an outer peripheral surface of the porous ceramic is greater than a root mean square slope RΔq in a roughness curve of a main surface of the porous ceramic.