Measuring the carriers' multiplication in Si and SiC power devices by α and γ radioactive sources

Abstract:
A non-invasive technique based on the irradiation with α and γ particles from an Am241 radioactive sources is proposed to characterize quantitatively the carriers’ multiplication occurring in Si and SiC power devices biased in pre-breakdown conditions. The technique is demonstrated on Si and SiC devices rated over 1.2 kV. Results of α irradiation in Si devices is in good agreement with TCAD simulation results and parametric approximations. Under the same biasing conditions, the multiplication of carriers generated by ionizing radiation in Si devices is shown to be lower than in SiC. Multiplication is also shown to depend on the range of the ionizing radiation, producing a slightly lower multiplication measured by α than by γ irradiation.