The physical and electronic properties of SiC make it the
foremost semiconductor material for short wavelength optoelectronic,
high temperature, radiation resistant, and high-power/high-frequency
electronic devices. A summary of the most important properties
in comparison to Si and GaAs is shown below:
| 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. |
Collectively, these properties allow SiC devices to offer
tremendous benefits over other available semicondutor devices
in a large number of industrial and military applications.
* Measurement parallel to c-axis.
|
