Abstract: The sintered body includes boron carbide, wherein a volume ratio of grains of the boron carbide having a grain size greater than 1 ?m and less than or equal to 4 ?m is 61% to 86% based on a volume ratio of total grains on a surface of the sintered body.

Abstract: The sintered body including silicon oxide and carbon, wherein the sintered body has a D band peak at a wave number of 1,311 cm?1 to 1,371 cm?1 and a G band peak at a wave number of 1,572 cm?1 to 1,632 cm?1 in a Raman spectrum, and wherein the D band peak or the G band peak have a higher intensity than a fifth peak present at a wave number of 1,027 cm?1 to 1,087 cm?1 in the Raman spectrum, is disclosed.

Abstract: The sintered body including boron carbide, wherein the sintered body includes a zone, in which a volume ratio of grains having a grain size of greater than 30 ?m and 60 ?m or less is in a range of 50% to 70% based on a total volume of grains, as observed on a surface of the sintered body, is disclosed.

Abstract: A manufacturing method of a ring-shaped element for an etcher, comprises a granulation operation comprising i) a slurry manufacturing process of preparing a slurry by mixing a raw material including boron carbide, a sinterability enhancer with a solvent; and ii) a granulation process of drying the slurry to prepare granulated raw material; a molding operation of manufacturing a green body by molding the granulated raw material; a sintering operation of carbonizing and sintering the green body to manufacture a sintered body; a shape operation of shaping the sintered body to a ring-shaped element for an etcher. The sinterability enhancer comprises one selected from the group consisting of carbon, boron oxide and combinations thereof.

Abstract: A boron carbide sintered body includes necked boron carbide-containing particles. The thermal conductivity of the boron carbide sintered body at 400° C. is 27 W/m·K or less and the ratio of the thermal conductivity of the boron carbide sintered body at 25° C. to that of the boron carbide sintered body at 800° C. is 1:0.2 to 1:3.

Abstract: A ring-shaped element for an etcher includes a body portion having an outer diameter surface connecting an outer contour of an upper surface and an outer contour of a bottom surface, and an inner diameter surface connected to an inner contour of the upper surface, and a mounting portion having an upper surface connected to the inner diameter surface of the body portion at a position lower than the upper surface of the body portion, and an inner diameter surface connecting an inner contour of the upper surface and an inner contour of a bottom surface. The upper surface of the mounting portion is stepped from the upper surface of the body portion to constitute a substrate mounting portion. The surface or entire body of the ring-shaped element includes necked boron carbide-containing particles, and the thermal conductivity of the ring-shaped element at 400° C. is 27 W/m·K or less.