Lower-temperature fabrication of airbridges by grayscale lithography to increase yield of nanowire transmons in circuit QED quantum processors

Research output: Contribution to journalJournal articleResearchpeer-review

Documents

Quantum hardware based on circuit quantum electrodynamics makes extensive use of airbridges to suppress unwanted modes of wave propagation in coplanar-waveguide transmission lines. Airbridges also provide an interconnect enabling transmission lines to cross. Traditional airbridge fabrication produces a curved profile by reflowing resist at elevated temperature prior to metallization. The elevated temperature can affect the coupling energy and even yield of pre-fabricated Josephson elements of superconducting qubits, tunable couplers, and resonators. We employ grayscale lithography to enable reflow and thereby reduce the peak temperature of our airbridge fabrication process from 200 to 150 °C and link this change to a substantial increase in the physical yield of transmon qubits with Josephson elements realized using Al-contacted InAs nanowires.

Original languageEnglish
Article number024004
JournalApplied Physics Letters
Volume123
Issue number2
Number of pages6
ISSN0003-6951
DOIs
Publication statusPublished - 10 Jul 2023

Bibliographical note

Publisher Copyright:
© 2023 Author(s).

ID: 361078436