With the development of energy saving and emission reduction, new energy grid connection and smart grid, the performance index and reliability of power semiconductor devices are increasingly required in these fields, which require higher working voltage, greater current carrying capacity, higher working frequency, higher efficiency, higher working temperature, stronger heat dissipation capacity and higher reliability. After more than half a century of development, the performance of power semiconductor devices based on silicon materials has approached its physical limit. Therefore, the development of the third generation semiconductor materials, such as silicon carbide (SiC) and gallium nitride (GaN), has been paid attention to. Technology-leading countries and large international enterprises have invested in the research and development and industrialization of silicon carbide and gallium nitride, and the industrial chain covers materials, devices, modules and applications.