Silicon carbide presents electrical properties suitable for many applications especially for high voltage devices. 6H-SiC p+nn+ structures have been fabricated following ISE software simulation in order to show blocking voltage as high as 1.5 kV. In particular, these diodes are realised by surrounding the emitter by a p-type region called JTE (Junction Termination Extension). The p+ region and JTE were formed by multiple aluminium implantation at 300 °C on n-type epilayer (10 µm 61015 cm 3), followed by an anneal at 1700 °C during 30 min. Current-voltage characteristics at 300 K show good rectifying properties. In reverse bias, the curve presents two distinct zones. In the first part, the current increases as VR1/2, which is corresponding to the generation/recombination of minority carrier in the space charge region, up to VR = 400 V. When the JTE is totally deserted, for VR  400 V, the current rises quickly until breakdown, which appears at the emitter edge (700 < VBR < 1000 V). This result is confirmed by OBIC (Optical Beam Induced Current) measurements on several diodes. An OBIC signal peak emerges at the JTE edge for VR  400 V, but at VR  600 V an other peak appear at the p+ region periphery. These results are in a good qualitative agreement with those obtained from simulations. These measurements completed by electrical characteristics at several temperatures will be analysed in this paper. The role of electrical activation of aluminium and surface effects will be discussed.