A new concept for the design and realization of metal based single electron devices: Step edge cut-off

To increase the operating temperature of a single electron circuit, it is necessary to reduce the capacitance of the tunnel junction. Usually this is done by reducing the linewidth of the capacitor forming metal stripes, which are sandwiched with an intermediate insulator. The use of alternative materials, however, allows capacitance reduction by means of thicker isolation layers or by a capacitor geometry different from a sandwich. The new SECO (step edge cut off) method, for the fabrication of single electron devices will be presented.