Physical & Electronic Properties of SiC Compared to GaAa and Si
Wide Energy Bandgap (eV)
4H-SiC: 3.26 6H-SiC: 3.03 GaAs: 1.43 Si: 1.12
Electronic devices formed in SiC can operate at extremely high temperatures without suffering from intrinsic conduction effects because of the wide energy bandgap. Also, this property allows SiC to emit and detect short wavelength light which makes the fabrication of blue light emitting diodes and nearly solar blind UV photodetectors possible.
High Breakdown Electric Field [V/cm (for 1000 V operation)]
4H-SiC: 2.2 x 106* 6H-SiC: 2.4 x 106* GaAs: 3 x 105 Si: 2.5 x 105
SiC can withstand a voltage gradient (or electric field) over eight times greater than than Si or GaAs without undergoing avalanche breakdown. This high breakdown electric field enables the fabrication of very high-voltage, high-power devices such as diodes, power transitors, power thyristors and surge suppressors, as well as high power microwave devices. Additionally, it allows the devices to be placed very close together, providing high device packing density for integrated circuits.
High Thermal Conductivity (W/cm · K @ RT)
4H-SiC: 3.0-3.8 6H-SiC: 3.0-3.8 GaAs: 0.5 Si: 1.5
SiC is an excellent thermal conductor. Heat will flow more readily through SiC than other semiconductor materials. In fact, at room temperature, SiC has a higher thermal conductivity than any metal. This property enables SiC devices to operate at extremely high power levels and still dissipate the large amounts of excess heat generated.
High Saturated Electron Drift Velocity [cm/sec (@ E ≥ 2 x 105 V/cm)]
4H-SiC: 2.0 x 107 6H-SiC: 2.0 x 107 GaAs: 1.0 x 107 Si: 1.0 x 107
SiC devices can operate at high frequencies (RF and microwave) because of the high saturated electron drift velocity of SiC.
