Two-dimensional Optical Beam Induced Current measurements in 4H-SiC bipolar diodes

This paper illustrates the photon´s absorption phenomenon in 4H-SiC. It shows two-dimensional Optical Beam Induced Current measurements (2D-OBIC) in 4H-SiC bipolar diodes. Two different diode structures were studied: the first one is a circular MESA protected avalanche diode with an optical window, and the second structure is a PN diode protected with a junction termination extension layer. The results provided an image of the electric field distribution in the diode surface. These measurements validate the efficiency of the used protection. The effect of radius at the periphery of the diode was also studied. Structural defects are explored by a variation of photo-current at this local point.