Perimeter and Area Components in the I-V Curves of 4H-SiC Vertical p+-i-n Diode With Al+ Ion-Implanted Emitters

This paper describes the separation between the area and the perimeter current density components of 4H-SiC vertical p(+)-i-n diode with a circular Al+ implanted emitter of different diameters in the range 150-1000 mu m and for temperatures of measurement in the range 30-290 degrees C. It is shown that before the diode series resistances become dominant, the forward current is given by the sum of an area plus a perimeter component, both of exponential trend with ideality factor 2; while toward high voltages, an area component with exponential trend and ideality factor 1 adds to the previous components. Moreover, this paper shows that forward area and perimeter current density components can be used for a straightforward identification of the parameters controlling the current transport, provided that they can be fit by the p-n junction equations in the frame of the abrupt junction approximation. Finally, this paper shows that the area reverse current density can be used for the identification of the electrically active defects in the drift layer.