Current status and perspectives of ultrahigh-voltage SiC power devices

Recent progress in the SiC material and ultrahigh-voltage devices is reviewed. Regarding the material issues, fast epitaxial growth of high-purity epitaxial layers and reduction of basal plane dislocations have made significant strides. Growth technology of 100 μm-thick epitaxial layers intentionally doped to 1 × 1014 cm−3 with a basal plane dislocation density of 0.1 cm−2 has been established. The carrier lifetimes can remarkably be enhanced by several techniques and trials of lifetime control have been successful. Using very thick (> 100 µm) and high-purity epitaxial layers, 15-27 kV SiC pin diodes and various switching devices such as insulated gate bipolar transistors, thyristors, bipolar junction transistors, and metal-oxide-semiconductor field effect transistors have been demonstrated. Although the performance of these ultrahigh-voltage devices is promising, further improvement of the performance and reliability is mandatory for system applications. Technological challenges in both the material and device fabrication are discussed.