An improved method for manufacturing a matching pair of electrodes comprises the steps of: fabricating a first electrode with a substantially flat surface; depositing islands of an oxidizable material over regions of the surface; depositing a layer of a third material over the surface of the first electrode to form a second electrode; separating the first electrode from the second electrode; oxidizing the islands of oxidizable material, which causes the islands to expand; bringing the upper electrode and the lower electrode into close proximity, whereupon the expanded island of oxidizable material touches the upper surface and creates an insulating gap between the two surfaces, thereby forming a matching pair of electrodes.