1、 SiC single crystal growth: In 1955, Lely et al. first proposed a sublimation technique for preparing silicon carbide crystals, which opened up a new era in the preparation of silicon carbide materials and device manufacturing. Unfortunately, due to the limited crystal size, irregular shape, and tendency to contain multiple crystal forms obtained by this method, it is difficult to apply it to actual device manufacturing. In 1978, Tairov et al. successfully solved the problem of polycrystalline nucleation by introducing SiC seed crystals into the low-temperature zone of the upper part of a graphite crucible, providing the possibility for controlled growth of high-quality large-sized silicon carbide single crystals. This method is known as the Improved Lely Method or Physical Vapor Transport (PVT) method, and is currently the main method used in industrial production.

The most important feature of the improved Lely method is the introduction of SiC seed crystals during the SiC growth process to ensure the stability of the SiC crystal structure, making the seed crystals as "seeds" particularly important during growth. In addition to requiring the seed crystal to have a specific off-axis angle (usually 4 °), it is also required that the surface shape, resistivity, defects, and other indicators of the seed crystal be controlled within a certain range. Among them, the defects that must be controlled include growth defects such as microtubes, polymorphism, wrapping, uneven color, hexagonal voids, as well as processing defects such as scratches, broken edges, cracks, and pits.

Qualified seed crystals selected layer by layer are bonded and loaded into the furnace. Silicon carbide raw materials are decomposed and sublimated at high temperatures, transported from the material surface to the surface of the upper seed crystal, and then deposited and crystallized on the growth surface of the seed crystal, ultimately forming silicon carbide single crystal ingots. 2、 SiC ingot processin:

The surface and surroundings of the silicon carbide ingot that has been taken out of the furnace are irregular. It needs to undergo X-ray orientation, rolling, and grinding to form a smooth cylindrical shape with standard dimensions before entering the key step of ingot processing: cutting, which uses precision cutting techniques to divide the SiC ingot into multiple thin slices. At present, the main cutting technologies include mortar wire cutting, diamond wire cutting, and laser peeling technology. Among them, mortar wire cutting uses abrasive containing wires and mortar to cut SiC ingots. Among several methods, it is the most traditional method with lower cost, but slower cutting speed, and may leave a deeper damage layer on the substrate surface. These deep damages cannot be effectively removed even after subsequent grinding and CMP processes, and are prone to inheriting and producing defects such as scratches and step lines in epitaxial processes.