No abstract

We present results of a planar process development based on the combination of electron-beam lithography and dry etching for fabricating high-quality superconducting photosensitive structures in the nm 100 sub  regime. The devices were fabricated by the application of an intrinsic proximity effect suppression procedure which makes the need for an elaborated correction algorithm redundant for planar design layouts which are orders of magnitude smaller than the backscattering length. In addition, we discuss the necessary considerations for extending the fabrication spatial scale of optical contactlithography with a mercury arc-discharge photon source down to the order of the exposure photon's wavelength ( µm sub ), thereby minimizing the writing time on the electron-beam lithograph. Finally we developed a unique and novel technique for controlling the undercut during a planar lift-off fabrication procedure without cleaving the wafer.

Abstract. We present an analysis of magnetoconductivity measurements on NbN thin films and nanostructures as they are used for superconducting nanowire single-photon detectors. Especially the temperature-dependence of the fluctuation conductivity near the zero-field transition temperature was studied in detail. Together with complementary measurements of the optical constants of NbN films with varying thickness, strategies for improving the absorptivity in NbN thin films are developed.

No abstract

No abstract