Ohmic contacts to moderately doped semiconductors—are they really Ohmic or low-barrier Schottky contacts?

We discuss experimental properties and possibilities of the maximum barrier height assessment for low Schottky barrier heights which have apparently Ohmic I–V curves. It is shown that the usage of numerical methods for low barrier height parameters extraction is very useful. We discuss the properties of the Schottky contacts with the same barrier heights but different semiconductor doping concentrations. For such contacts there can be an accumulation or depletion layer at the semiconductor surface for the same barrier height depending on the doping concentration. I–V curves of such structures have similar character, but a rather large difference can be expected in C–V curves.