High values of the ideality factorn, in the range 1–6, have been found at low temperatures in highly dopedn++p+junctions with phosphorous and gallium or boron diffusion profiles. By studying the thermal activation of the forward current it has been possible to establish that tunneling related to charge carrier transport plays a decisive role for the generation of the highnfactors. The tunneling component can be explained by the presence of local electric fields, much higher than the average field in the space‐charge region, and the tunneling becomes more evident forp‐njunctions with higher concentration of shallow dopants at the interception point between thep+and then++concentration profiles. The use of a specially designed method based on deep‐level transient spectroscopy has made it possible to conclude that the recombination centers, contributing to the recombination current, are positioned in then++phosphorous emitter and have the same properties for gallium and boronpbase profiles. The concentration of isolated recombination centers decreases with increasing phosphorous concentrations due to clustering or precipitation, and increases the electric field constrictions.