For the development and improvement of the next generations of SiC devices, new methods are needed to accurately measure device properties, such as doping concentration, local potential and electric fields. In this paper we investigate a derivative effect of the secondary electron doping contrast (SEDC) in the scanning electron microscope (SEM) [1-3], namely that we can visualize the local potential in a cleaved cross-section of the power device. The potential can then be manipulated by using in-situ nanoprobing to apply a voltage to the p-n contacts.The SEDC is caused by potential differences due to the doping of the sample. The primary electron of the SEM scatters inelastically with the valence electrons in the semiconductor. Some of these valence electrons gain enough energy, so that they can escape the semiconductor becoming secondary electrons (SEs) and be detected. As shown in Fig. 1, the minimum kinetic energy required is equal to the potential difference between the detector level E_detect and the valence band edge E_v. This potential difference \Delta E_effective is smaller for p-doped areas than it is for n-doped areas, resulting in more SEs being detected, which is why p-doped areas appear brighter than n-doped areas in the SEM. Variations in the local doping concentration cause small potential differences, resulting in a small change in detected SEs and thus a small gray value difference in the resulting SEM image. Therefore, the SEDC can also be seen as potential contrast [3, 4].To manipulate the potential further, we can use in-situ nanoprobing. On our sample, the p-doped area was implanted on top of an epitaxially grown n-doped area. An external voltage is applied to the p-doped area. An overview SEM image of this setup with the nanoprobing needle touching the sample metallization is shown in Fig. 2. A SEM image with 0 V applied at the junction is given in Fig. 3 (a) and for comparison images with -4 V and +4 V applied are shown in (b) and (c) respectively.Line profiles were taken across the p-n junction for all measured images between -4 and +4 V and are given in Fig. 3 (d). With a larger negative bias, the signal in the p-doped region increases, whereas it decreases with a larger positive bias. The line profiles of the images taken with +3 and +4 V are almost identical, because the diode opens at about +3 V, shorting the two terminals. The measured gray value can thus directly be translated into a local potential, which may be compared to TCAD simulations. The increase in width of the space charge region can also be observed. The technique presented in this paper maps the local potential of the sample. Therefore, it can improve the development of SiC devices in areas where the knowledge and management of the electric field distribution is crucial, such as improving the edge termination, increasing radiation hardness and protecting the gate oxide. Additionally, the technique would allow TCAD simulations to be calibrated.This work was funded by the Austrian Research Promotion Agency (FFG, Project No. 905107).[1] M. Moser et al., Materials Science Forum, Vol. 1089, pp. 23–29 (2023). [2] C. Sealy et al., Journal of Electron Microscopy, Vol. 49(2), pp 311-321 (2000). [3] J. Cazaux, Journal of Electron Microscopy, Vol 61(5), pp 261-284 (2012). [4] R. Rosenkranz, Journal of Materials Science: Materials in Electronics, Vol 22, pp 1523-1535 (2011).