Light-impermeable, high purity silicon carbide material, a light shielding member for a semiconductor-treating apparatus, and a semiconductor-treating apparatus
AssigneeNGK Insulators, Ltd.
InventorsMasao Nishioka, Naotaka Kato
Life of this patent
Estimating the term…
Abstract
A light-impermeable, high purity silicon carbide material including polycrystals of silicon carbide as a main ingredient, wherein the silicon carbide material has a porosity of not more than 0.1%, the content of each of metal elements contained in the silicon carbide material is not more than 200 ppb, a weight ratio of silicon relative to the entire weight of the silicon carbide material is 69.00 to 69.90 wt %, and a light transmittance of the silicon carbide material in a wavelength range of 0.4 to 25 .mu.m is not more than 0.05% per a thickness of 0.5 mm.
Claims6
A light-impermeable, high purity silicon carbide material comprising polycrystals of silicon carbide as a main ingredient, wherein the silicon carbide material has a porosity of not more than 0.1%, the content of each of metal elements contained in the silicon carbide material is not more than 200 ppb, a weight ratio of silicon relative to the entire weight of the silicon carbide material is 69.00 to 69.90 wt %, and a light transmittance of the silicon carbide material in a wavelength range of 0.4 to 25 .mu.m is not more than 0.05% per a thickness of 0.5 mm.
Dependencies are inferred from the claim text.