In the process of semiconductor manufacturing, graphite materials are widely used in epitaxy, etching and other processes because of their excellent high temperature performance and processability. However, graphite materials themselves have problems such as high porosity, easy oxidation, and particle release. Silicon carbide (SiC) coating technology can effectively improve the corrosion resistance, high temperature resistance and service life of components by depositing high-purity and dense SiC coatings on the surface of graphite substrates.

In SiC coating technology, CVD is a widely used method for the preparation of high-purity and high-density SiC coatings. This technology introduces gas precursors containing silicon and carbon into the reaction chamber at high temperature to react on the surface of the substrate to form SiC coatings. The CVD process can precisely control the film thickness, composition and crystallinity, and can cover a variety of complex structures.

SiC coatings offer key performance advantages: strong corrosion resistance, capable of fully wrapping the graphite base to avoid damage by corrosive gases; high thermal conductivity and high bonding strength with the graphite base, ensuring that the coating is not easy to fall off after multiple high-temperature and low-temperature cycles; good chemical stability, avoiding coating failure in high-temperature corrosive atmospheres. In addition, the thermal expansion coefficient of SiC is less different from that of graphite, making it suitable as the preferred material for graphite base surface coatings.

In specific application scenarios, products such as SiC-coated graphite bases and SiC-coated crystal boats have been applied in LED chip epitaxy, SiC epitaxy, GaN epitaxy and other fields. A complete production line covering graphite purification, precision processing to CVD coating is the key to ensuring product batch consistency.