Defect energy levels in hydrogen-implanted and electron-irradiated n-type 4H silicon carbide

The energy position and thermal stability of deep levels in nitrogen doped 4H-SiC epitaxial layers were studied after 1.2 MeV proton implantation and 15MeV electron irradiation using deep level transient spectroscopy (DLTS). The DLTS measurements which were carried out in the temperature range from 120 to 630 kappa after each annealing step, reveal the presence of ten electron traps located in the energy range of 0.45-1.6 eV below the conduction band edge.