The breakdown failure points in the 4H-SiC PiN diodes were analyzed by the electron beam induced current (EBIC). We focused on the failure, which showed the avalanche breakdown, and we determined the failure points by an emission microscopy. We observed the basal plane dislocation around the failure point and at measured temperatures below 200K we found the dark spots in the EBIC. However, in the X-ray topography image, no spots were found around the dislocations. We therefore think that these spots originated from the metal contamination. The electric field was multiplied due to a permittivity change, and this multiplication caused the avalanche breakdown.