Al+ Implanted Anode for 4H-SiC p-i-n Diodes

Abstract

Simulations of hole injection and forward current-voltage characteristics of Al+ implanted 4H-SiC p-i-n diodes have been performed for different values of hole densities in the ion implanted anode anddifferent thicknesses of the base. Both the parameters are more elevated for thinner base valuesbecause of a less effective recombination but identical injection and increase with the increasing ofthe anode hole density up saturate because of a reduced effective majority carrier density in theelectrodes with respect to real majority carrier density values due to the 4H-SiC band gap shrinkingup to an effective carrier saturation. For Al p-type doping of 4H-SiC simulations show effectivecarrier of few units 1E18 cm-3 and saturation to 5E18 cm-3 for real hole density > 5E18 cm-3. In Al+ implanted 4H-SiC such hole density values can be obtained for implanted Al concentration of about 2E20 cm-3 and 1950 °C/5 min annealing.