Fabrication and test of Superconducting Single Photon Detectors

We report here on the state of our fabrication process for Superconducting Single Photon Detectors (SSPDs). We have fabricated submicrometer SSPD structures by electron beam lithography using very thin (10 nm) NbN films deposited by DC-magnetron sputtering on different substrates and at room substrate temperature. The structures show a fast optical response (risetime < 500 ps limited by readout electronics) and interesting self-resetting features.