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

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 and different thicknesses of the base. Both the parameters are more elevated for thinner base values because of a less effective recombination but identical injection and increase with the increasing of the anode hole density up saturate because of a reduced effective majority carrier density in the electrodes with respect to real majority carrier density values due to the 4H-SiC band gap shrinking up to an effective carrier saturation. For Al p-type doping of 4H-SiC simulations show effective carrier of few units 10(18) cm(-3) and saturation to 5 x 10(18) cm(-3) for real hole density >= 5 x 10(18) cm(-3). In Al+ implanted 4H-SiC such hole density values can be obtained for implanted Al concentration of about 2 x 10(20) cm(-3) and 1950 degrees C/5 min annealing.