2nd Generation Features of SiC MOSFETs

Since the dielectric breakdown strength of SiC (silicon carbide) is about 10 times as high as that of Si (silicon), SiC power devices can offer a high withstand voltages and low voltage drops. The on-resistance per unit area can be reduced in SiC devices compared with that of Si for the same withstand voltage.
Bipolar IGBT devices are commonly used as high-voltage transistors of 1000V or higher in Si. IGBT bipolar operation works with two types of carriers, electrons and holes, by injecting minority carriers, holes, into the drift layer, thereby lowering the resistance in the drift layer. However, the disadvantage of bipolar operation is the tail current generated at turn-off due to the accumulation of minority carriers, which increases turn-off loss.
On the other hand, since SiC MOSFETs are a unipolar device that operates only with electrons even in high-voltage products, no tail current is generated, and compared to Si IGBTs, the turn-off loss is reduced. Therefore, SiC MOSFETs are capable of operation in the high frequency range, which is difficult with Si IGBTs, and passive component also contributes to design miniaturization.

Toshiba’s TW070J120B 1200V 2nd Generation SiC MOSFETs switches faster than a conventional silicon Si IGBT (low-gate input charges, etc.)