Production process of silicon carbide substrate

The production process of silicon carbide substrate mainly includes the following steps: First, the preparation of raw materials. Si and C need to be synthesized into SiC polycrystalline particle powder in a ratio of 1:1. The particle size and purity will directly affect the quality of the crystal. The second is the selection of seed crystals. Seed crystals are the substrate for crystal growth, providing the basic lattice structure for crystal growth, which will also affect the quality of the crystal. Then there is crystal growth, which is the core process of SiC substrate production. The main methods include physical vapor transport, high-temperature chemical vapor deposition and liquid phase method. Next is the ingot processing, which is oriented by an X-ray single crystal orientation instrument, and then flattened and rounded, the seed crystal surface is removed, the dome surface is removed, and it is processed into a silicon carbide crystal of standard diameter size. Then there is crystal cutting, which cuts the grown crystal into sheets. Since the hardness of silicon carbide is second only to diamond and it is a high-hardness and brittle material, the cutting process is time-consuming and easy to crack. The main cutting methods are mortar wire cutting, diamond wire multi-wire cutting and laser irradiation stripping. Next is wafer grinding and polishing, which processes the substrate surface to an atomic-level smooth plane. Commonly used abrasives include high-hardness abrasives such as boron carbide and diamond. Finally, wafer cleaning and testing are used to remove residual particles and metal impurities during the processing process, and conduct comprehensive quality inspections.