Improvements in silicon oxide dielectric loss for superconducting microwave detector circuits

Published

January 24, 2013

Author(s)

Dale Li, Jason Austermann, James A. Beall, Daniel T. Becker, Hsiao-Mei Cho, Anna E. Fox, Nils Halverson, Jason Henning, Gene C. Hilton, Johannes Hubmayr, Jeffrey L. Van Lanen, John P. Nibarger, Michael D. Niemack, Kent D. Irwin

Abstract

Dielectric loss in low-temperature superconducting integrated circuits can cause lower overall efficiency, particularly in the 90 to 220 GHz regime. We present a method to tune the dielectric loss for silicon oxide deposited by plasma-enhanced chemical-vapor deposition at ambient temperatures. Deposition in an environment with a higher silane-to-oxygen ratio produces silicon oxide films with a lower loss-tangent and a slightly higher optical index of refraction, while contributing no appreciable change in film stress. We measured the dielectric loss by fabricating a series of Nb- SiO_x-Nb microstrip resonators in the frequency range of 6 to 9 GHz and comparing their temperature dependence to a model of parasitic two-level-system fluctuators. The dielectric loss-tangent of silicon oxide was improved from 6 × 10^-3 for stoichiometric silicon dioxide to 2 × 10^-3 for a more silicon-rich silicon oxide. We present details of the fabrication process and measurements of microstrip resonators.

Citation

IEEE Transactions on Applied Superconductivity

Volume

23

Issue

3

Pub Type

Journals

Download Paper

https://doi.org/10.1109/TASC.2013.2242951

Keywords

silicon-oxide, dielectric, efficiency, loss tangent, ECR, PECVD, microwave resonators

Citation

Li, D. , Austermann, J. , Beall, J. , Becker, D. , Cho, H. , Fox, A. , Halverson, N. , Henning, J. , Hilton, G. , Hubmayr, J. , Van, J. , Nibarger, J. , Niemack, M. and Irwin, K. (2013), Improvements in silicon oxide dielectric loss for superconducting microwave detector circuits, IEEE Transactions on Applied Superconductivity, [online], https://doi.org/10.1109/TASC.2013.2242951 (Accessed November 21, 2024)