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SiC substrate can have microscopic defects, such as Threading Screw Dislocation (TSD), Threading Edge Dislocation (TED), Base Plane Dislocation (BPD), and others. These defects are caused by deviations in the arrangement of atoms at the atomic level.

Silicon carbide (SiC) has important applications in areas such as power electronics, high-frequency RF devices, and sensors for high-temperature-resistant environments due to its excellent physicochemical properties. However, the slicing operation during SiC wafer processing introduces damages on the surface, which, if left untreated, can expand during the subsequent epitaxial growth process and form epitaxial defects, thus affecting the yield of the device.

A SiC boat, short for silicon carbide boat, is a high-temperature-resistant accessory used in furnace tubes to carry wafers during high-temperature processing. Due to the outstanding properties of silicon carbide such as resistance to high temperatures, chemical corrosion, and excellent thermal stability, SiC boats are extensively utilized in various thermal treatment processes including diffusion, oxidation, Chemical Vapor Deposition (CVD), and annealing.

Defect-free epitaxial growth occurs when one crystal lattice has nearly identical lattice constants to another. Growth happens when lattice sites of the two lattices at the interface region are approximately matched, which is possible with a small lattice mismatch (less than 0.1%). This approximate matching is achieved even with elastic strain at the interface, where each atom is slightly displaced from its original position in the boundary layer. While a small amount of strain is tolerable for thin layers and even desirable for quantum well lasers, the strain energy stored in the crystal is generally lowered by the formation of misfit dislocations, which involve a missing row of atoms in one lattice.

The development of 3C-SiC, a significant polytype of silicon carbide, reflects the continuous advancement of semiconductor material science. In the 1980s, Nishino et al. first achieved a 4 μm thick 3C-SiC film on a silicon substrate using chemical vapor deposition (CVD)[1], laying the foundation for 3C-SiC thin-film technology.

In semiconductor manufacturing, the precision and stability of the etching process are paramount. One critical factor in achieving high-quality etching is ensuring that wafers are perfectly flat on the tray during the process.