Modeling of the cosmic radiation-induced failure mechanism in high power devices

Ion irradiation experiments provide valuable insight into the failure mechanism caused by cosmic radiation in power devices. After penetrating into the semiconductor, ions lose their kinetic energy in the vicinity of the surface. Applying sufficiently high reverse voltage, an incident ion induces a high electric field peak at the anode side of a power device which, by impact ionization, generates a highly conductive filament, while it propagates towards the cathode. In contrast with such experiments, natural cosmic rays may cause a nuclear reaction anywhere within the volume of a device, through which recoil ions can be produced. In this case, two electric field peaks form and propagate in opposite direction, respectively. This process represents the basic mechanism leading to cosmic radiation-induced failures of power devices.