Monocrystalline and Polycrystalline SiC in EADS Astrium Space Applications

Abstract:

Of all the wide bandgap semiconductors, SiC is currently the most attractive material for aerospace applications. It offers significant advantages at high temperatures and high voltage levels while benefiting from an excellent thermal conductivity, the resistance to a harsh radiation environment (in particular in medium low orbits (MEO) where the Van Allan belts show a high concentration of electron and proton radiation) and an advanced materials technology. Due to the significant progress in the last years in monocrystalline SiC material fabrication and process technology, the space industry is increasingly interested in exploiting the SiC characteristics for electronic application. Although the requirement for space components are highly demanding with space qualified technological processes required, it is expected that high quality commercial SiC components submitted to a stringent screening process will allow the realisation of highly reliable space components. Electronic applications of monocrystalline SiC for space mainly exploit the high breakdown electric field which allows for lower specific on-resistances due to high doping and thinner drift region layers in vertical SiC power device structures. Among all SiC power devices, high voltage rectifiers have reached the highest degree of maturity. EADS Astrium has started evaluation activities of commercially available 1200 V SiC diodes and also 4.5 kV diodes developed in the frame of the ESA CHPCA (components for high power conditioning application) project. One application is power supply of ion thrusters on satellites which require electric power in the range of 2 to 8 kW at voltages of 1 to 2 kV. Mechanical aerospace applications of polycrystalline SiC