Abstract

High sensitivity ultrafast nanowire superconducting single photon detectors (SSPD) in the near infrared wavelength range have been fabricated with ultrathin (3.5nm) NbN films grown on R-plane sapphire substrates by dc reactive magnetron sputtering in Ar+N₂ mixture [1]. The main drawback of this approach is that in order to obtain the superconducting 5 cubic fee phase of NbN the substrate must be heated up to 900°C during deposition, which makes it difficult to integrate the detector with waveguides and microcavities, typically realized on other substrates (such as GaAs and Si) and not compatible with these temperatures.

© 2007 IEEE