5 MeV Proton and 15 MeV Electron Radiation Effects Study on 4H-SiC nMOSFET Electrical Parameters

The impact of proton and electron irradiations on the electrical parameters of 4H-SiC nMOSFETs has been investigated by the time bias stress instability method. This study has allowed observing the effect of holes trapped in the gate oxide together with the generated interface traps. Improvements of important electrical parameters, such as the threshold voltage, the effective mobility and the maximum drain current were observed. These improvements could be connected with the Nitrogen and residual Hydrogen atoms diffusion from the SiO2/SiC interface toward the epilayer during irradiation. These atoms are likely to create other bonds by occupying the Silicon and Carbon’s dangling bond vacancies. This way, the number of passivated Carbon atoms is increased, hence improving the SiO2/SiC interface quality.