Wafer-scale uniformity of Dolan-bridge and bridgeless Manhattan-style Josephson junctions for superconducting quantum processors

Journal article (2024)

Authors

N. Muthusubramanian QN/Kavli Nanolab Delft - AS
M. Finkel QCD/DiCarlo Lab - QuTech Advanced Research Centre
W.J. Duivestein QN/Groeblacher Lab - AS
C. Zachariadis QN/Kavli Nanolab Delft - AS
S.L.M. van der Meer QCD/DiCarlo Lab - QuTech Advanced Research Centre
H.M. Veen QCD/DiCarlo Lab - QuTech Advanced Research Centre
M.C. Beekman BUS/TNO STAFF - QuTech Advanced Research Centre , TNO
T. Stavenga QCD/DiCarlo Lab - QuTech Advanced Research Centre
A. Bruno QN/Kavli Nanolab Delft - AS
L. DiCarlo QCD/DiCarlo Lab - QuTech Advanced Research Centre , QN/DiCarlo Lab - AS
Research Group
QN/Kavli Nanolab Delft (AS) (TU Delft)
Copyright: © 2024 N. Muthusubramanian, M. Finkel, W.J. Duivestein, C. Zachariadis, S.L.M. van der Meer, H.M. Veen, M.C. Beekman, T. Stavenga, A. Bruno, L. DiCarlo
DOI
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https://doi.org/10.1088/2058-9565/ad199c
Scalability Transmon Through-silicon vias Frequency targeting Dolan-bridge junction Manhattan-style junction
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Published Date

2024

Language

English

Faculty

Applied Sciences

Department

QN/Quantum Nanoscience

Research Group

QN/Kavli Nanolab Delft

Abstract

We investigate die-level and wafer-scale uniformity of Dolan-bridge and bridgeless Manhattan-style Josephson junctions, using multiple substrates with and without through-silicon vias (TSVs). Dolan junctions fabricated on planar substrates have the highest yield and lowest room-temperature conductance spread, equivalent to ∼ 100 M H z in transmon frequency. In TSV-integrated substrates, Dolan junctions suffer most in both yield and disorder, making Manhattan junctions preferable. Manhattan junctions show pronounced conductance decrease from wafer center to edge, which we qualitatively capture using a geometric model of spatially-dependent resist shadowing during junction electrode evaporation. Analysis of actual junction overlap areas using scanning electron micrographs supports the model, and further points to a remnant spatial dependence possibly due to contact resistance.