Numerical simulations of Al implanted 4H-SiC diodes modeling an explicit carrier trap effect due to the non-substitutional Al doping concentration

In this paper the experimental results on the conduction characteristics of Al implanted 4H-SiC p-i-n diodes are investigated by mean of numerical simulations. An explicit carrier trap effect, due to the deep defects created by the ion implantation process, was considered during the simulations. In order to model the trap activity, the effective defect density was set as a fraction of the chemical Al doping profile and the location of the traps, within the material energy gap, was assumed related to the Al acceptor energy level, i.e about 200 meV from the valence band edge. The incomplete ionization of substitutional Al atoms was also taken into account. A forward current density of about 370 A/cm² could be achieved at 5 V and T = 298 K.