Silicon Carbide is a chemical compound of carbon and silicon. It was originally produced by a high temperature electro-chemical reaction of sand and carbon. Silicon carbide is an excellent abrasive and has been produced and made into grinding wheels and other abrasive products for over one hundred years. Today the material has been developed into a high quality technical grade ceramic with very good mechanical properties. It is used in abrasives, refractories, ceramics, and numerous high-performance applications. The material can also be made an electrical conductor and has applications in resistance heating, flame igniters and electronic components. Structural and wear applications are constantly developing.

Key Properties of Silicon Carbide (SiC)

  • Low density
  • High strength
  • Low thermal expansion
  • High thermal conductivity
  • High hardness
  • High elastic modulus
  • Excellent thermal shock resistance
  • Superior chemical inertness

Silicon carbide is composed of carbon and silicon atoms with strong bonds in the crystal lattice. This produces a very hard and strong material. Silicon carbide is not attacked by any acids or alkalis or molten salts up to 800°C. In air, SiC forms a protective silicon oxide coating at 1200°C and is able to be used up to 1600°C. The high thermal conductivity coupled with low thermal expansion and high strength gives this material exceptional thermal shock resistant qualities. Silicon carbide ceramics with little or no grain boundary impurities maintain their strength to very high temperatures, approaching 1600°C with no strength loss. Chemical purity, resistance to chemical attack at temperature, and strength retention at high temperatures has made this material very popular as wafer tray supports and paddles in semiconductor furnaces.

The electrical conduction of SiC has lead to its use in resistance heating elements for electric furnaces, and as a key component in thermistors (temperature variable resistors) and in varistors (voltage variable resistors).

Silicon carbide (SiC) is a material for advanced semiconductor electronic device applications. SiC-based electronics and sensors can operate in hostile environments (600 C = 1112 F GLOWING RED HOT!) where conventional silicon-based electronics (limited to 350 C) cannot function. Silicon carbide’s ability to function in high temperature, high power, and high radiation conditions will enable large performance enhancements to a wide variety of systems and applications.

The large performance gains made possible by SiC’s high-temperature high-power capabilities offer economically large performance benefits to the aircraft, automotive, communications, power, and spacecraft industries.The tremendous advantages of SiC electronics in these specific applications are slowly becoming a reality. SiC’s immature crystal growth and device fabrication technologies are being developed, but they are not yet sufficiently developed to the degree required for reliable system incorporation. Developing and maturing SiC technology to the point that it is ready for widespread system insertion is the focus of increasingly intense research efforts at laboratories around the world.

SiC devices have repeatedly demonstrated proper operation at temperatures as high as 650 C. Silicon-based semiconductor electronics cannot function at these temperatures.

It seems Silicon Carbide (SiC) will replace silicon in the power electronics components for aerospace, automotives, industrial applications. If the cost of SiC devices come down, their coverage will extend to consumer electronics applications too.