On the Nature of a Soldered Contact on a Semiconductor

Semiconductor circuit elements

“…The base contact itself may introduce a small series resistance of this kind. I n silicon the base contact has been found to be almost non-rectifying, with a resistance for unit area of about 10-60hmm2 (Putley 1947), whilst in germanium it has been suggested that the transition fiom the metal of a soldered contact to the semiconductor is of a continuous nature, and introduces little extra resistance (Pantchechnikoff 1950). Although the base contact is never in fact completely non-rectifying, the voltage drop across it may usually be neglected in comparison with that across the spreading resistance R,, which arises from the constricted current flow in the semiconductor near the rectifying contact.…”