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Robustness of Dolan-bridge and Manhattan-style Josephson junctions in through-silicon via integrated substrates

ORAL

Abstract

Vertical input-output routing of signals using metallized through-silicon vias (TSVs) is a promising path to scaling monolithic superconducting quantum processors. Bridgeless (i.e., Manhattan) junctions have been believed to be less sensitive to resist height variations compared to Niemeyer-Dolan bridge junctions, therefore benefiting frequency targeting of qubits in the presence of TSVs.  We compared the performance of Manhattan and Dolan-style variants of Josephson junctions fabricated on TSV-integrated substrates. The residual standard deviation of junction resistances is 30% lower on average for Manhattan-style junctions than Dolan-bridge junctions at the intra-die level in the TSV layout. The number of defective junctions (opens and shorts) is one order of magnitude lower in Manhattan-style junctions. Comparison of resistance of identically patterned junctions between planar and TSV dies shows a near doubling of resistance only for the Dolan-bridge variant in the TSV layout. Ongoing optimization of the resist stack and junction pattern post-processing steps tailored for TSV-integrated substrates may further narrow the resistance spread of Manhattan-style junctions.

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Publication: Benchmarking frequency targeting robustness of superconducting qubits on planar and TSV-integrated substrates (planned paper)

Presenters

  • Nandini Muthusubramanian

    QuTech, Kavli Institute of Nanoscience, Delft University of Technology, Delft University of Technology

Authors

  • Nandini Muthusubramanian

    QuTech, Kavli Institute of Nanoscience, Delft University of Technology, Delft University of Technology

  • Christos Zachariadis

    QuTech and Kavli Institute of Nanoscience, Delft University of Technology, The Netherlands, Delft University of Technology, QuTech, Kavli Institute of Nanoscience, Delft University of Technology

  • Sean van der Meer

    QuTech, Kavli Institute of Nanoscience, Delft University of Technology, QuTech and Kavli Institute of Nanoscience, Delft University of Technology, The Netherlands

  • Marc Beekman

    Netherlands Organisation for Applied Scientific Research, Netherlands Organisation for Applied Scientific Research, The Netherlands, QuTech and Netherlands Organisation for Applied Scientific Research, The Netherlands

  • Matvey Finkel

    Delft University of Technology, QuTech, Kavli Institute of Nanoscience, Delft University of Technology, QuTech and Kavli Institute of Nanoscience, Delft University of Technology, The Netherlands

  • Alessandro Bruno

    QuTech and Kavli Institute of Nanoscience, Delft University of Technology, The Netherlands, Delft University of Technology, QuTech, Kavli Institute of Nanoscience, Delft University of Technology, QuTech and Kavli Institute of Nanoscience, Delft University of Technology, and Quantware, B.V., The Netherlands

  • Leonardo DiCarlo

    QuTech and Kavli Institute of Nanoscience, Delft University of Technology, The Netherlands, Delft University of Technology