Reliability of SiC Power Devices Against Cosmic Radiation-Induced Failure

Abstract

Cosmic radiation has been identified as a decisive factor for power device reliability. Energetic neutrons create ionizing recoils within the semiconductor substrate which may lead to device burnout. While this failure mode has gained widespread acceptance for power devices based on silicon the question whether a similar mechanism could also lead to failure of SiC devices was left to be debated. Radiation hardness intrinsic to the SiC material was generally assumed but as experimental data was scarce reliability problems due to radiation-induced device failure could not be ruled out. Recent accelerated testing results now show that cosmic radiation will indeed affect the reliability of SiC power devices, as it is the case for its silicon counterpart, but the problem can be contained very effectively by device design.