Current Status and Emerging Trends in Wide Bandgap (WBG) Semiconductor Power Switching Devices

The current state-of-the-art of wide bandgap (WBG) semiconductor material technology is reviewed for the manufacturing of high-performance and reliable power electronics switching devices. In particular, silicon carbide (SiC) and gallium nitride (GaN) material and device technologies are evaluated when compared to conventional silicon power switching devices. For commercial applications above 400 volts, SiC stands out as a viable near-term commercial opportunity especially for single-chip current ratings in excess of 20 amps. For voltage ratings below 900 volts and smaller currents (below 20 amps), lateral GaN power transistors that utilize two-dimensional electron gas (2DEG) are promising candidates. At the time of this writing, field-reliability of WBG power devices is yet to be demonstrated in power converter applications. The exact role of high-density of material defects in both SiC and GaN semiconductors, primarily in the drift-region of the device, is not known from manufacturing and reliability considerations. This fundamental understanding is critical in order for WBG power devices to rapidly penetrate the vast commercial and strategic markets.