GHz counting rate NbN single-photon detector for IR diagnostics of VLSI CMOS circuits

We present a new, simple to manufacture superconducting single-photon detector operational in the range from ultraviolet to mid-infrared radiation wavelengths. The detector combines GHz counting rate, high quantum efficiency and very low level of dark (false) counts. At 1.3-1.5 mum wavelength range our detector exhibits a quantum efficiency of 5-10%. The detector photoresponse voltage pulse duration was measured to be about 150 ps with jitter of 35 ps and both of them were limited mostly by our measurement equipment. In terms of quantum efficiency, dark counts level, speed of operation the detector surpasses all semiconductor counterparts and was successfully applied for CMOS integrated circuits diagnostics. (C) 2003 Elsevier B.V. All rights reserved.