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Fabrication of Transmon Qubits with Molecular-Beam Epitaxy Aluminum

ORAL

Abstract

I will discuss the design, fabrication, and measurement of a superconducting transmon qubit, made mostly from molecular-beam epitaxy (MBE) aluminum. To reduce loss at superconductor-substrate interface, the qubit incorporates a thin film of aluminum grown by MBE on a high resistivity silicon substrate.[1] The initial MBE aluminum layer is patterned using photolithography and wet etching. An Al/AlOx/Al Josephson junction is then added using electron-beam lithography, an ion milling of the initial layer, and double angle evaporation of aluminum by electron-beam evaporation with an oxidation step in between. I will discuss the process and present some transmon and resonator coherence data.
[1] Brian M McSkimming, et al. Journal of Vacuum Science & Technology A, 35, 021401 (2017).

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Presenters

  • Yizhou Huang

    Department of Physics, University of Maryland, College Park, University of Maryland, College Park

Authors

  • Yizhou Huang

    Department of Physics, University of Maryland, College Park, University of Maryland, College Park

  • Frederick C Wellstood

    University of Maryland, College Park, Department of Physics, University of Maryland, College Park

  • Christopher J K Richardson

    Laboratory for Physical Sciences, Laboratory of Physical Sciences, University of Maryland, College Park

  • Benjamin Palmer

    Laboratory for Physical Sciences, University of Maryland, College Park