4 - SiC power device design and fabrication

Abstract

Silicon carbide (SiC) is one of the wide bandgap semiconductor materials and its wide bandgap and high thermal stability make it possible to operate the SiC devices at very high junction temperatures of over 200°C. The main advantage of SiC for power device application is its low resistance for the drift region even when designed to support large voltage. This favors the development of high-voltage unipolar devices which have much superior switching speed than bipolar structures. The SiC Schottky barrier diodes (SiC-SBDs) were released in the market in early 2000s, and SiC metal-oxide-field-effect transistors (SiC-MOSFETs) were in mid- or late-2000s. At this time, many industries are produced and distributed SiC power devices, especially SiC-SBDs and SiC-MOSFETs, and are taking advantage of the benefits of SiC power devices like the volume and the weight reduction of a power supply or an inverter. Also, since the built-in potential of SiC pn junction is as high as ~2.5V in room temperature, the on-state voltage drop of bipolar device becomes high. Therefore, the development of ultrahigh-voltage pin diodes and insulated gate bipolar transistors (IGBTs) have been given significant attention among the researches for very high voltage devices. For example, ultrahigh-voltage and low loss power devices are key components for future smart grids and high-voltage power supplies.