This application provides a low-resistivity
polycrystalline silicon carbide bulk material and its preparation method and apparatus. The method involves using isostatically pressed
graphite as a substrate, first loading it into a
reaction mechanism and creating a sealed negative pressure environment through vacuum. Then, the furnace body is heated in sections to a set
deposition temperature. Subsequently,
argon,
hydrogen,
methyltrichlorosilane, and
nitrogen are sequentially introduced to achieve the set pressure within the furnace, and deposition is carried out at this temperature to obtain a
silicon carbide deposit. Finally, the
gas supply is stopped, the gas inside the furnace is replaced with
nitrogen, and the product is removed after controlled cooling to
room temperature. Through vacuum sealing, sectioned
temperature control, precise
gas supply, and stable pressure deposition, the uniform distribution of reaction gases and the full progress of the reaction are effectively ensured, significantly improving the density, thickness uniformity, and compositional stability of the
silicon carbide deposit. Simultaneously, stable
nitrogen doping is achieved, resulting in a low-resistivity, high-purity, crack-free, and defect-free
polycrystalline silicon carbide bulk material. The process offers strong
controllability and good product consistency, meeting the stringent application requirements of high-end industrial fields.