TY - JOUR
T1 - Wafer-scale uniformity of Dolan-bridge and bridgeless Manhattan-style Josephson junctions for superconducting quantum processors
AU - Muthusubramanian, N.
AU - Finkel, M.
AU - Duivestein, W.J.
AU - Zachariadis, C.
AU - van der Meer, S.L.M.
AU - Veen, H.M.
AU - Beekman, M.W.
AU - Stavenga, T.
AU - Bruno, A.
AU - DiCarlo, L.
PY - 2024
Y1 - 2024
N2 - 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.
AB - 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.
KW - transmon
KW - scalability
KW - through-silicon vias
KW - frequency targeting
KW - Dolan-bridge junction
KW - Manhattan-style junction
UR - http://www.scopus.com/inward/record.url?scp=85184001857&partnerID=8YFLogxK
U2 - 10.1088/2058-9565/ad199c
DO - 10.1088/2058-9565/ad199c
M3 - Article
SN - 2058-9565
VL - 9
JO - Quantum Science and Technology
JF - Quantum Science and Technology
IS - 2
M1 - 025006
ER -