Growth of amorphous tungsten silicide and study of the proximity effect at low dimensions for superconducting applications

Abstract

In this thesis we successfully fabricate Superconducting Nanowire Single Photon Detectors (SNSPDs) out of a hybrid film with layers of both niobium nitride (NbN) and amorphous tungsten silicide (WSi). These hybrid devices use the proximity effect to potentially be more efficient than either of the materials alone. In order to make these devices, we first grew high quality samples of tungsten silicide and characterized them before growing hybrid films useful for nanoscale devices. We tested a hybrid chip with a number of nanowire devices expecting more efficient and faster detectors than the material alone. Though the findings are promising with the devices having reset times of around 2 ns and jitter of around 50 ps the devices did not saturate indicating that further experiments are needed to characterize the hybrid devices.