Low-loss superconducting resonators fabricated from tantalum films grown at room temperature
Abstract The use of α -tantalum in superconducting circuits has enabled a considerable improvement in the coherence time of transmon qubits. The standard approach to grow α -tantalum thin films on silicon involves heating the substrate, which takes several hours per deposition and prevents the integration of this material with wafers containing temperature-sensitive components. We report a detailed experimental study of an alternative growth method of α -tantalum on silicon, which is achieved at room temperature through the use of a niobium seed layer. Despite a substantially higher density of oxygen-rich grain boundaries in the films sputtered at room temperature, resonators made from these films are found to have state-of-the-art quality factors, comparable to resonators fabricated from tantalum grown at high temperature. This finding challenges previous assumptions about correlations between material properties and microwave loss of superconducting thin films, and opens a new avenue for the integration of tantalum into fabrication flows with limited thermal budget.
Authors
- Esha A. Umbarkar
- Guillaume Marcaud (ORCID: https://orcid.org/0000-0002-4694-7262)
- Neha Mahuli (ORCID: https://orcid.org/0000-0001-8218-5536)
- Matthew A. Hunt (ORCID: https://orcid.org/0000-0002-8445-2914)
- Abdul K. Rumaiz (ORCID: https://orcid.org/0000-0002-9907-299X)
- Cherno Jaye (ORCID: https://orcid.org/0000-0001-6158-6373)
- Yuan He (ORCID: https://orcid.org/0009-0000-4672-8388)
- Daniel A. Fischer (ORCID: https://orcid.org/0000-0002-3072-6000)
- Cliff Chen (ORCID: https://orcid.org/0009-0009-1424-2039)
- David Perello (ORCID: https://orcid.org/0000-0002-5353-0991)
- Conan Weiland (ORCID: https://orcid.org/0000-0001-6808-1941)
- Shahriar Aghaeimeibodi (ORCID: https://orcid.org/0000-0002-9920-493X)
- Noel D’Souza (ORCID: https://orcid.org/0000-0003-1810-1785)
- Sandra Díez (ORCID: https://orcid.org/0000-0002-8249-1426)
- Rachel Resnick
- Victoria Ly (ORCID: https://orcid.org/0009-0005-3988-4266)
- Jiansong Gao
- Oskar Painter (ORCID: https://orcid.org/0000-0002-1581-9209)
- Ignace Jarrige
Institutions
- National Institute of Standards and Technology (US)
- Brookhaven National Laboratory (US)
- Material Measurement Laboratory (US)
Publication Details
- Journal
- Communications Materials
- Published
- 2025-08-16
- DOI
- https://doi.org/10.1038/s43246-025-00897-x
- Citations
- 8
- Primary Topic
- Quantum and electron transport phenomena
- Type
- article
- Field-Weighted Citation Impact
- 9.97
Funders
- U.S. Department of Energy
- National Institute of Standards and Technology
- Office of Science
- Brookhaven National Laboratory