On-chip stencil lithography for superconducting qubits

Applied Physics Reviews, vol. 13

Abstract

Improvements in circuit design and, more recently, in materials and surface cleaning have contributed to a rapid development of coherent superconducting qubits. However, organic resists commonly used for shadow evaporation of Josephson junctions (JJs) pose limitations due to residual contamination, poor thermal stability, and compatibility under typical surface-cleaning conditions. To provide an alternative, we developed an inorganic SiO2/Si3N4 on-chip stencil lithography mask for JJ fabrication. The stencil mask is resilient to aggressive cleaning agents and it withstands high temperatures up to 1200 °C, thereby opening new avenues for JJ material exploration and interface optimization. To validate the concept, we performed shadow evaporation of Al-based transmon qubits followed by stencil mask liftoff using vapor hydrofluoric acid, which selectively etches SiO2. We demonstrate an average T1≈75±11 μs over a 200 MHz frequency range across multiple cooldowns for one device, and T1≈44±8 μs for a second device. These results confirm the compatibility of stencil lithography with state-of-the-art superconducting quantum devices and motivate further investigations into materials engineering, film deposition, and surface cleaning techniques.

Authors 24

1. Roudy Hanna Aachen

   Forschungszentrum Jülich · Jülich Aachen Research Alliance · RWTH Aachen University

   Affiliation as printed

   PGI-9, Forschungszentrum Jülich and JARA Jülich-Aachen Research Alliance 1 , Jülich,

   RWTH Aachen University 2 , 52062 Aachen,

2. Sören Ihssen

   Karlsruhe Institute of Technology

   Affiliation as printed

   IQMT, Karlsruhe Institute of Technology 3 , 76344 Eggenstein-Leopoldshafen,

3. Simon Geisert

   Karlsruhe Institute of Technology

   Affiliation as printed

   IQMT, Karlsruhe Institute of Technology 3 , 76344 Eggenstein-Leopoldshafen,

4. Umut Koçak Aachen

   Forschungszentrum Jülich · Jülich Aachen Research Alliance · RWTH Aachen University

   Affiliation as printed

   PGI-9, Forschungszentrum Jülich and JARA Jülich-Aachen Research Alliance 1 , Jülich,

   RWTH Aachen University 2 , 52062 Aachen,

5. Matteo Arfini

   Delft University of Technology

   Affiliation as printed

   Kavli Institute of Nanoscience, Delft University of Technology 4 , Lorentzweg 1, 2628 CJ Delft,

6. Albert Hertel

   Forschungszentrum Jülich · Jülich Aachen Research Alliance

   Affiliation as printed

   PGI-9, Forschungszentrum Jülich and JARA Jülich-Aachen Research Alliance 1 , Jülich,

7. Thomas J. Smart

   Forschungszentrum Jülich · Jülich Aachen Research Alliance

   Affiliation as printed

   PGI-9, Forschungszentrum Jülich and JARA Jülich-Aachen Research Alliance 1 , Jülich,

8. Michael Schleenvoigt

   Forschungszentrum Jülich · Jülich Aachen Research Alliance

   Affiliation as printed

   PGI-9, Forschungszentrum Jülich and JARA Jülich-Aachen Research Alliance 1 , Jülich,

9. Tobias Schmitt

   Forschungszentrum Jülich · Jülich Aachen Research Alliance

   Affiliation as printed

   PGI-9, Forschungszentrum Jülich and JARA Jülich-Aachen Research Alliance 1 , Jülich,

10. Kaycee Underwood

    Forschungszentrum Jülich · Jülich Aachen Research Alliance

    Affiliation as printed

    PGI-9, Forschungszentrum Jülich and JARA Jülich-Aachen Research Alliance 1 , Jülich,

11. Abdur Rehman Jalil

    Forschungszentrum Jülich · University of Würzburg · Jülich Aachen Research Alliance

    Affiliation as printed

    Institute for Experimental Physics III, University of Würzburg 5 , 97074 Würzburg,

    PGI-10, Forschungszentrum Jülich and JARA Jülich-Aachen Research Alliance 6 , Jülich,

12. Jin Hee Bae

    Forschungszentrum Jülich · Jülich Aachen Research Alliance

    Affiliation as printed

    PGI-9, Forschungszentrum Jülich and JARA Jülich-Aachen Research Alliance 1 , Jülich,

13. Benjamin Bennemann

    Forschungszentrum Jülich · Jülich Aachen Research Alliance

    Affiliation as printed

    PGI-10, Forschungszentrum Jülich and JARA Jülich-Aachen Research Alliance 6 , Jülich,

14. Mathieu Féchant

    Karlsruhe Institute of Technology

    Affiliation as printed

    IQMT, Karlsruhe Institute of Technology 3 , 76344 Eggenstein-Leopoldshafen,

15. M. E. Field

    Karlsruhe Institute of Technology

    Affiliation as printed

    IQMT, Karlsruhe Institute of Technology 3 , 76344 Eggenstein-Leopoldshafen,

16. Martin Spiecker

    Karlsruhe Institute of Technology

    Affiliation as printed

    IQMT, Karlsruhe Institute of Technology 3 , 76344 Eggenstein-Leopoldshafen,

17. Nicolas Zapata

    Karlsruhe Institute of Technology

    Affiliation as printed

    IQMT, Karlsruhe Institute of Technology 3 , 76344 Eggenstein-Leopoldshafen,

18. Christian Dickel

    University of Cologne

    Affiliation as printed

    Physics Institute II, University of Cologne 7 , 50937 Köln,

19. Erwin Berenschot

    University of Twente

    Affiliation as printed

    Mesoscale Chemical Systems, MESA+Institute, University of Twente 8 , 7500 AE Enschede,

20. Niels R. Tas

    University of Twente

    Affiliation as printed

    Mesoscale Chemical Systems, MESA+Institute, University of Twente 8 , 7500 AE Enschede,

21. Gary A. Steele

    Delft University of Technology

    Affiliation as printed

    Kavli Institute of Nanoscience, Delft University of Technology 4 , Lorentzweg 1, 2628 CJ Delft,

22. Detlev Grützmacher Aachen

    Forschungszentrum Jülich · Jülich Aachen Research Alliance · RWTH Aachen University

    Affiliation as printed

    PGI-10, Forschungszentrum Jülich and JARA Jülich-Aachen Research Alliance 6 , Jülich,

    PGI-9, Forschungszentrum Jülich and JARA Jülich-Aachen Research Alliance 1 , Jülich,

    RWTH Aachen University 2 , 52062 Aachen,

23. Ioan M. Pop

    University of Stuttgart · Karlsruhe Institute of Technology

    Affiliation as printed

    IQMT, Karlsruhe Institute of Technology 3 , 76344 Eggenstein-Leopoldshafen,

    PHI, Karlsruhe Institute of Technology 9 , 76131 Karlsruhe,

    Physics Institute 1, Stuttgart University 10 , 70569 Stuttgart,

24. Peter Schüffelgen

    Forschungszentrum Jülich · Jülich Aachen Research Alliance

    Affiliation as printed

    PGI-9, Forschungszentrum Jülich and JARA Jülich-Aachen Research Alliance 1 , Jülich,