Low-loss Nb on Si superconducting resonators from a dual-use spintronics deposition chamber and with acid-free post-processing
Abstract
Magnetic impurities are known to degrade superconductivity. For this reason, physical vapor deposition chambers that have previously been used for magnetic materials have generally been avoided for making high-quality superconducting resonator devices. In this article, we show by example that such chambers can be used for this purpose; with Nb films sputtered in a chamber that continues to be used for magnetic materials, we demonstrate compact (3 μm gap) coplanar waveguide resonators with low-power internal quality factors near one million. We achieve this using a resist strip bath with no post-fabrication acid treatment, which results in performance comparable to previous strip baths with acid treatments. We also find evidence that this improved resist strip bath provides a better surface chemical template for post-fabrication hydrogen fluoride processing. These results are consistent across three Si substrate preparation methods, including a 700 °C anneal. These results will inform nanofabrication for other superconducting materials and the integration of magnetic materials for hybrid systems.
Article Details
Journal Info
Applied Physics Letters
American Institute of Physics
Authors (16)
Maciej W. Olszewski
Department of Physics, Cornell University 1 , Ithaca, New York 14853,
Jadrien T. Paustian
Department of Physics, Syracuse University 2 , Syracuse, New York 13244-1130,
Tathagata Banerjee
School of Applied and Engineering Physics, Cornell University 3 , Ithaca, New York 14853,
Haoran Lu
College of Chemistry, Key Laboratory of Theoretical & Computational Photochemistry of Ministry of Education
Jorge L. Ramirez
Department of Physics, University of Colorado Boulder 4 , Boulder, Colorado 80309,
Nhi Nguyen
Kiichi Okubo
Department of Physics, Syracuse University 2 , Syracuse, New York 13244-1130,
Rohit Pant
Laboratory for Physical Sciences 6 , 8050 Greenmead Dr, College Park, Maryland 20740,
Aleksandra B. Biedron
NY Creates 8 , Albany, New York 12203,
Daniel C. Ralph
Christopher J. K. Richardson
Laboratory for Physical Sciences 6 , 8050 Greenmead Dr, College Park, Maryland 20740,
Gregory D. Fuchs
Corey Rae H. McRae
Department of Physics, University of Colorado Boulder 4 , Boulder, Colorado 80309,
Ivan V. Pechenezhskiy
Department of Physics, Syracuse University 2 , Syracuse, New York 13244-1130,
B. L. T. Plourde
Department of Physics, Syracuse University 2 , Syracuse, New York 13244-1130,
Valla Fatemi
School of Applied and Engineering Physics, Cornell University 3 , Ithaca, New York 14853,