Silicon carbide characteristics
Silicon carbide materials also named carborundum are widely used in ceramic ball bearings, valves, semiconductor materials, gyros, measuring instruments, aerospace and other fields, and have become an irreplaceable material in many industrial fields.
Silicon carbide is a natural superlattice and a typical homogeneous polymorph. Since the difference between the Si and C diatomic layer stacking sequences leads to different crystal structures, there are more than 200 (currently known) homogeneous polytypes. Therefore, SiC is very suitable for use as a new generation of light-emitting diode (LED) substrate materials, high-power power electronic materials.
Physical property
High hardness-3000kg/mm2, can cut Ruby
High wear resistance, just behind diamond
The thermal conductivity is 3 times of Sic and 8-10times of GaAs,
Thermal stability of SIC is on high side, impossible to melt at atmospheric pressure.
Good heat dissipation performance, very important for high power devices
Good resistant to corrosion and can resist almost any known corrosive agent at room temperature.
The surface of sic is easy to oxidize to form a thin layer of SIO2, which an prevent further oxidation
When temperature higher then 1700 degree, the oxide film melts and oxidize rapidly
The band gap of 4-sic and 6h sic is about 3 times of Si, 2times of GaAs, the breakdown electric field intensity is higher then Si by an order of magnitude, and the saturated electron drift velocity is 2.5times of Si, the band gap of 4H SiC is wider then 6h SiC.
