Simulation and exerimental results on the forward J-V characteristic of Al implanted 4H-SiC p-i-n diodes

In this work the forward J-V characteristics of 4H–SiC p–i–n diodes are analysed by means of a physics based device simulator tuned by comparison to experimental results. The circular devices have a diameter of 350 microns. The implanted anode region showed a plateau aluminium concentration of 6E19 cm-3 located at the surface with a profile edge located at 0.2 microns and a profile tail crossing the n -type epilayer doping at 1.35 microns. Al atom ionization efficiency was carefully taken into account during the simulations. The final devices showed good rectifying properties and at room temperature a diode current density close to 370 A/cm2 could be measured at 5 V. The simulation results were in good agreement with the experimental data taken at temperatures up to about 523 K in the whole explored current range extending over nine orders of magnitude. Simulations also allowed to estimate the effect of a different p+ doping electrically effective profile on the device current handling capabilities.