Investigation of the Impact of Neutron Irradiation on SiC Power MOSFETs Lifetime by Reliability Tests

High temperature reverse-bias (HTRB), High temperature gate-bias (HTGB) tests and electrical DC characterization were performed on planar-SiC power MOSFETs which survived to accelerated neutron irradiation tests carried out at ChipIr-ISIS (Didcot, UK) facility, with terrestrial neutrons. The neutron test campaigns on the SiC power MOSFETs (manufactered by ST) were conducted on the same wafer lot devices by STMicroelectronics and Airbus, with different neutron tester systems. HTGB and HTRB tests, which characterise gate-oxide integrity and junction robustness, show no difference between the non irradiated devices and those which survived to the neutron irradiation tests, with neutron fluence up to 2x 1011 (n/cm2). Electrical characterization performed pre and post-irradiation on different part number of power devices (Si, SiC MOSFETs and IGBTs) which survived to neutron irradiation tests does not show alteration of the data-sheet electrical parameters due to neutron interaction with the device.

Automated summary

High temperature reverse-bias (HTRB) and High temperature gate-bias (HTGB) tests were conducted on planar-SiC power MOSFETs that survived neutron irradiation tests, showing no difference in performance compared to non-irradiated devices. Electrical characterization pre and post-irradiation on different power devices also did not reveal any alteration of electrical parameters due to neutron interaction with the devices.