Silicon Carbide Power Diodes

The Silicon Carbide power diodes were specifically designed for protection of solar cells arrays in solar panels mounted in satellites and space exploration modules. The first batches of devices are currently used for two European Space Agency missions, BepiColombo and Solar Orbiter.

These diodes developed by CSIC with the colaboration of Alte Technology (ATN) have the peculiarity of their unusually wide operation temperature range, from -170ºC up to 300ºC which is  possible thanks to the use of Silicon Carbide instead of Silicon as bare material.

Silicon Carbide is a so called Wide Band Gap semiconductor, and presents superior electrical and physical characteristics to Silicon, making it particularly suitable for high power, high temperature and high frequency electronic applications. Silicon Carbide is currently used in power electronics applications such as hybrid and electric cars, renewable energies, power supplies, train transportation, but in a standard operation temperature range from -40ºC up to 175ºC.

Additionally to the use of Silicon Carbide as semiconductor material for high temperature, a specific and robust processing and packaging technology have been developed. The internal device structure differs from standard commercial SiC diodes. The interconnections and the package have been optimized specifically for the semiconductor die to take a full benefit of the SiC intrinsic performances.

ATN has been in charge of the electrical, environmental and reliability test campaigns. The feedback from ATN studies helped to optimize the final design and fabrication process of the device. As the operation range of these devices was unusual, no characterisation standards were available, and an adaptation of current ESA ESCC standards have been done by ATN and ESA specialists. A specific screening and qualification campaign have been designed and performed. This can be used as base line for the future definition of novel high temperature devices test standards.

This device is the first Spanish component included in the European Space Agency European Preferred Part List (EPPL).  However, the diodes could be used in other high temperature applications.

Space qualified Silicon Carbide power diodes have been developed by the CNM-CSIC power group in Barcelona in close collaboration with ATN and produced by D+T Microelectrónica in the CNM-CSIC large scale facility (ICTS) and qualified by Alter Technoology Optoelectronics and New Technologies division in Tres Cantos (Madrid). From now on, these parts will be handled as ALTER TECHNOLOGY specific product for high reliability and harsh environment related markets.