Triggering Mechanism for Neutron Induced Single-Event Burnout in Power Devices

Cosmic ray neutrons can trigger catastrophic failures in power devices. It has been reported that parasitic transistor action causes single-event burnout (SEB) in power metal--oxide--semiconductor field-effect transistors (MOSFETs) and insulated gate bipolar transistors (IGBTs). However, power diodes do not have an inherent parasitic transistor. In this paper, we describe the mechanism triggering SEB in power diodes for the first time using transient device simulation. Initially, generated electron--hole pairs created by incident recoil ions generate transient current, which increases the electron density in the vicinity of the n - /n + boundary. The space charge effect of the carriers leads to an increase in the strength of the electric field at the n - /n + boundary. Finally, the onset of impact ionization at the n - /n + boundary can trigger SEB. Furthermore, this failure is closely related to diode secondary breakdown. It was clarified that the impact ionization at the n - /n + boundary is a key point of the mechanism triggering SEB in power devices.