Oxygen-induced graphitization of amorphous carbon deposit on ohmic switch contacts improves their electrical conductivity and protects them from wear

There has been a resurgence of interest in developing ohmic switches to complement transistors in order to address challenges associated with electrical current leakage and lowering power consumption. A critical limitation is the reliability of their electrical contacts, which are prone to wear and hydrocarbon-induced contamination. These phenomena progressively inhibit signal transmission, eventually leading to device failure. We report on progress made towards converting the contamination into a highly conductive material. We show that Pt-coated microswitch contacts operating in the presence of O₂ experience limited contaminant accumulation even in hydrocarbon-rich environments. We then demonstrate that devices that have experienced contamination can recover their original performance when operated in a clean N₂:O₂ environment. Auger and Raman spectroscopy indicate that this resistance recovery is associated with the structural transformation of the contaminant as opposed to its removal and that the transformed contaminant may shield the Pt coating from wear. (paper)