Superconducting nanowire single-photon detectors fabricated from atomic-layer-deposited NbN
Risheng Cheng, Sihao Wang, Hong X. Tang · Applied Physics Letters · 2019
High-quality ultrathin films of niobium nitride (NbN) are developed by the plasma-enhanced atomic layer deposition (PEALD) technique. Superconducting nanowire single-photon detectors patterned from this material exhibit high switching currents and saturated internal efficiencies over a broad bias range at a telecommunication wavelength of 1550 nm. Statistical analyses on hundreds of fabricated devices show a near-unity throughput yield due to the exceptional homogeneity of the films. The ALD-NbN material represents an ideal superconducting material for fabricating large single-photon detector arrays combining high efficiency, low jitter, and low dark counts.