Experimental Measurements of Constriction Resistance for Electrical Contacts Simulated Using Microfabrication

Contact resistance in electrical connectors is a consequence of both film resistance and constriction resistance. Film resistance is caused by a material's high resistivity (e.g., oxidized metals) or contamination of the material. Constriction resistance results from the narrowing of the current as it passes through the electrical connector. In this paper, we propose a method for evaluating how contact structure affects constriction resistance using physically simulated samples processed using microfabrication. The samples' physical structure was designed and fabricated arbitrarily with an electron-beam lithography system so that the complicated contact structure could be simulated physically. Several samples representing the contact-simulated structure with various distributions of "A-spots" were fabricated, and their electrical resistances were measured precisely. The influence of electrode thickness on constriction resistance was estimated based on these precise measurements. To compare the experimental result eliminating the influences with an expression for constriction resistance, the validity of our method with physically simulated samples was confirmed. By comparing the electrical resistances of various samples with different A-spot distributions, we were able to establish a relationship between contact structure and constriction resistance.