siliciumcarbide

Siliciumcarbide, commonly known as silicon carbide (SiC), is a binary chemical compound of silicon and carbon with the formula SiC. It occurs naturally as the mineral moissanite and was first discovered in 1893 by Henri Moissan in a meteor crater; it was later synthesized for industrial use. The name siliciumcarbide reflects its compositional elements.

SiC is extremely hard, with a Mohs hardness near 9, high thermal conductivity, and a very high melting point (about 2700 degrees Celsius). It is chemically inert and has a wide band gap that ranges from about 2.3 to 3.3 eV depending on the crystal polytype, making it suitable for high-temperature and high-power electronics as well as optoelectronic devices. It exists in many polytypes, including cubic 3C-SiC and hexagonal 4H-SiC and 6H-SiC, which differ in stacking and electronic properties.

Industrial production relies on carbothermic reduction of silica with carbon in electric furnaces to produce bulk SiC, which is then purified and processed into powders and grains. For semiconductor devices and coatings, SiC is grown by methods such as chemical vapor deposition (CVD) or sublimation growth, yielding single-crystal wafers and high-quality films.

Major applications include abrasive grains for grinding and cutting tools; refractory materials for high-temperature services; and electronics, including high-efficiency power diodes and transistors (Schottky diodes and MOSFETs) and ultraviolet light emitters. SiC is also used as a substrate for epitaxial growth of other wide-bandgap semiconductors and in radiation-tolerant components.

Safety and environmental notes: SiC is chemically inert and of relatively low toxicity, but inhalation of fine dust can irritate the respiratory tract; appropriate industrial hygiene practices are recommended.