Electrical Performance Advantages And Disadvantages Of Silicon Carbide Power Devices

Advantages：

1. High voltage resistance: Critical breakdown electric field is as high as 2MV/cm (4H-SiC), so it has higher voltage resistance (10 times that of Si).

2. Easy heat dissipation: Due to the higher thermal conductivity of SiC materials (three times that of Si), heat dissipation is easier and the device can operate at higher ambient temperatures. Theoretically, SiC power devices can operate at a junction temperature of 175 ℃, so the size of the heat sink can be significantly reduced.

3. Low conduction loss and switching loss: SiC material has twice the electron saturation speed of Si, making SiC devices have very low on-resistance (1/100 in Si), low conduction loss; SiC material has three times the bandwidth of Si, the leakage current is reduced by several orders of magnitude compared with the Si device, which can reduce the power loss of the power device; there is no current trailing phenomenon in the off process, low switching loss, which can reduce the power loss of the power device; there is no current trailing phenomenon in the off process, low switching loss. There is no current trailing during turn-off, low switching losses, and the switching frequency can be greatly increased for practical applications (10 times that of Si). 

4. can reduce the size of the power module: due to the high current density of the device (such as Infineon products up to 700A / cm), in the same power level, all-SiC power modules (SiC MOSFETsSiC SBD) package size is significantly smaller than the Si IGBT power modules.

Major Disadvantage: The major disadvantage of the Schottky diode is the relatively high reverse current. Due to its metal-semiconductor junction, it is more prone to leakage currents when the voltage is connected in the reverse direction. In addition, Schottky diodes tend to have a low maximum reverse voltage. They tend to have a maximum value of 50V or less. Keep in mind that the reverse voltage is the value at which the diode will breakdown and begin to conduct a large amount of current when the voltage is connected in the reverse direction (from the cathode to the anode). This means that a Schottky diode cannot withstand a large reverse voltage without breaking down and conducting a large amount of current. It will still leak a small amount of current even before it reaches its maximum reverse value.

Depending on the application and use of the circuit, this may prove to be significant or insignificant.