China Si Wafer Etching Manufacturers, Suppliers, Factory

In the high voltage field, particularly for high-voltage devices above 20,000V, the SiC epitaxial technology still faces several challenges. One of the main difficulties is achieving high uniformity, thickness, and doping concentration in the epitaxial layer. For the fabrication of such high-voltage devices, a 200um thick silicon carbide epitaxial wafer with excellent uniformity and concentration is required.

There are several materials currently under investigation, among which silicon carbide stands out as one of the most promising. Similar to GaN, it boasts higher operating voltages, higher breakdown voltages, and superior conductivity compared to silicon. Moreover, thanks to its high thermal conductivity, silicon carbide can be utilized in environments with extreme temperatures. Lastly, it is significantly smaller in size yet capable of handling greater power.

Chemical Vapor Deposition (CVD) refers to a process technology where multiple gaseous reactants at varied partial pressures undergo a chemical reaction under specific temperature and pressure conditions. The resulting solid substance deposits on the surface of the substrate material, thereby obtaining the desired thin film. In traditional integrated circuit manufacturing processes, the obtained thin film materials are generally compounds such as oxides, nitrides, carbides, or materials like polycrystalline silicon, amorphous silicon, etc.

The Silicon Carbide (SiC) production process encompasses the preparation of substrate and epitaxy from the materials side, followed by chip design and manufacturing, device packaging, and finally, distribution to downstream application markets. Among these stages, substrate material processing is the most challenging aspect of the SiC industry. SiC substrates are both hard and brittle, making cutting, grinding, and polishing extremely difficult. This increases the likelihood of defects during processing and reduces the yield rate. Currently, major international SiC manufacturers are planning to transition from 6-inch to 8-inch SiC wafers. Overcoming the challenges associated with 8-inch substrates has become a critical benchmark for the SiC industry. This article will introduce the key parameters of SiC substrates.

The history of silicon carbide (SiC) dates back to 1891, when Edward Goodrich Acheson accidentally discovered it while attempting to synthesize artificial diamonds. Acheson heated a mixture of clay (aluminosilicate) and powdered coke (carbon) in an electric furnace. Instead of the expected diamonds, he obtained a bright green crystal adhering to the carbon. This crystal had a hardness second only to diamond, and was thus named carborundum. In 1904, French-Jewish chemist Henri Moissan discovered rare natural silicon carbide minerals while studying meteorite samples from the Diablo Canyon in Arizona, USA. He named these minerals moissanite, and his discovery earned him the 1906 Nobel Prize in Chemistry.

Silicon carbide (SiC), a prominent structural ceramic, is renowned for its exceptional properties, including high-temperature strength, hardness, elastic modulus, wear resistance, thermal conductivity, and corrosion resistance. These attributes make it suitable for a wide range of applications, from traditional industrial uses in high-temperature kiln furniture, burner nozzles, heat exchangers, sealing rings, and sliding bearings, to advanced applications like ballistic armor, space mirrors, semiconductor wafer chucks, and nuclear fuel cladding.