Analyzing Neutron Sensitive Volume in SiC Power Devices Using Two Photon Laser Absorption

Abstract

This work focuses on identifying region-specific sensitive volume in wide bandgap Silicon Carbide (SiC) devices using the Two Photon Absorption (TPA) laser technique. Neutron-induced secondary particles exhibit random behavior and when these particles strike the sensitive volume of a device, they can cause catastrophic device failure, but the details of the mechanisms remain unclear. The TPA technique is used to deposit localized charge packets by focusing on different depths of the device, and measuring the resulting current transient. Experimental results clearly show distinct transients at three different depths within the device. These results were further compared with TCAD mixed mode simulation results to validate the observation. To the best of our knowledge, this study represents that, this is the first time, very fast (ns) transients have been captured in SiC power devices at high bias (400 V and 600 V) condition using Two photon Absorption (TPA) laser method.