Contribution to the Theory of the Silicon Carbide Contact

1. The high limiting contact voltage of 40 to 50 volts in contacts between silicon carbide members (single crystals of the black‐green variety) is explained on the basis of the known temperature‐voltage relation.2. Practically clean silicon carbide possesses a superficial layer which functions as a potential hill for the electrons. Because of its thinness the hill is penetrable for the electric current by means of the tunnel effect. The tunnel resistance per unit area was investigated with terminal areas of the order of 2 mm2. Being constant at small voltages, it drops down through some orders of magnitude within the voltage range of 0.5 to 5 volts, showing that the work function for emission of electrons into the barrier material from the adjacent metal is of the order of 3 electron volts. From the amount of the tunnel resistance it is concluded that the thickness of the potential hill is of the order of 10 to 20 Angstrom units. The simultaneity of applied voltage and tunnel current is demonstrated.