Radiation Tolerant High-Voltage Silicon Carbide Devices

Due to its wider band-gap and low minority carrier lifetimes, Silicon Carbide devices are also expected to be more radiation tolerant than Silicon power devices. However, lab tests conducted by NASA and others have found that commercially available Silicon Carbide devices are prone to failure at 30% of rated voltage when exposed to heavy ion radiation. The proposed phase I activity builds upon the work done at Rensselaer Polytechnic Institute to improve the SEB failure rate of Silicon Carbide devices. The team at RPI conducted detailed electrothermal simulations that revealed the device physics behind SEB failure of Silicon Carbide vertical devices. The team discovered that using a special epitaxial structure used to fabricate the devices, the SEB tolerance of Silicon carbide vertical devices can be increased from 30% to 80% of rated voltage. LogiSiC Devices is partnering with Rensselaer Polytechnic tonbsp;fabricatenbsp;of high speed 1200V, 40A Silicon Carbide Schottky rectifiers that are capable of withstanding heavy ion radiation up to 40 MeV-cm2/mg at up to 80% of rated voltage. The proposed Phase I effort will also extend the theoretical work performed at RPI to both study SEB failure mechanisms of Silicon Carbide MOSFETs and diodes and make specific recommendations for radiation-tolerant device structures across different voltage ranges.