High Voltage Si/SiC Hybrid Power Switch: An Ideal Next Step for SiC

Abstract In recent years wide-bandgap semiconductors such as Silicon Carbide (SiC) and Gallium Nitride (GaN) have gained importance in the semiconductor industry. This development is due in part to their ability to operate with reduced losses at higher voltages frequencies and temperatures than conventional Silicon (Si)-based devices. However a challenge currently faced in the industry is to manufacture these energy efficient power switches at lower cost so they can be used in energy efficient but cost sensitive applications such as solar converters medical equipment and uninterruptible power supplies (UPS). Researchers at NC State University have engineered a novel solution for this problem by combining the merits of two kinds of semiconductor devices unipolar and bipolar devices. Unipolar devices such as SiC-based MOSFET can work at high frequencies and bipolar devices such as Si-based IGBT provide higher energy efficiency at higher currents. This hybrid Si/SiC switch has been observed to achieve a significant 70% reduction in energy loss during switching operation. The hybrid Si/SiC switch costs only 71% as compared to the cost of manufacturing pure SiC-based devices.