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Title: Reducing intrinsic loss in superconducting resonators by surface treatment and deep etching of silicon substrates

We present microwave-frequency NbTiN resonators on silicon, systematically achieving internal quality factors above 1 M in the quantum regime. We use two techniques to reduce losses associated with two-level systems: an additional substrate surface treatment prior to NbTiN deposition to optimize the metal-substrate interface and deep reactive-ion etching of the substrate to displace the substrate-vacuum interfaces away from high electric fields. The temperature and power dependence of resonator behavior indicate that two-level systems still contribute significantly to energy dissipation, suggesting that more interface optimization could further improve performance.
Authors:
; ; ; ; ;  [1]
  1. QuTech Advanced Research Center and Kavli Institute of Nanosicence, Delft University of Technology, Lorentzweg 1, 2628 CJ Delft (Netherlands)
Publication Date:
OSTI Identifier:
22399007
Resource Type:
Journal Article
Resource Relation:
Journal Name: Applied Physics Letters; Journal Volume: 106; Journal Issue: 18; Other Information: (c) 2015 AIP Publishing LLC; Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
75 CONDENSED MATTER PHYSICS, SUPERCONDUCTIVITY AND SUPERFLUIDITY; DEPOSITION; ELECTRIC FIELDS; ENERGY LOSSES; ETCHING; INTERFACES; IONS; METALS; MICROWAVE RADIATION; NIOBIUM COMPOUNDS; OPTIMIZATION; PERFORMANCE; QUALITY FACTOR; RESONATORS; SILICON; SUBSTRATES; SURFACE TREATMENTS; TITANIUM NITRIDES