Ultra-high Q-factor superconducting tantalum resonators on 300 mm Si wafers

Authors:R. Acharya, D. Perez Lozano, Ts. Ivanov, S. Massar, C. Vrancken, Y. Canvel, Y. Li, A.M. Vadiraj, J. Van Damme, S. Aghaeimeibodi, A. Khalajhedayati, M. Mongillo, O. Painter, D. Wan, A. Potočnik, K. De Greve

Abstract:Superconducting resonators are central to superconducting quantum information technologies and essential for bosonic qubit architectures, where long-lived storage modes enable hardware-efficient error correction. Achieving ultra-high quality factors in scalable planar circuits is challenging because multiple dissipation channels contribute to the total loss. Here we report planar $\alpha$-Ta resonators fabricated on 300 mm ultra-high-resistivity ($>10$ k$\Omega$ cm) intrinsic silicon using industrial processes, achieving median internal Q factors exceeding 40 million and maxima above 60 million. Energy-participation-ratio analysis identifies a dominant participation-controlled interface loss mechanism and places conservative upper bounds on substrate-associated dissipation. For the best-performing substrate, the inferred substrate loss tangent is below $1.0 \times 10^{-8}$, establishing industrial MCZ silicon among the lowest-loss substrate platforms reported for superconducting resonators. At the same time, the exceptionally low losses show no clear correlation with commonly cited silicon substrate metrics such as room-temperature resistivity or impurity concentrations. More broadly, these studies establish industrial 300 mm processing, careful interface engineering, and 300 mm MCZ silicon substrates as a promising platform for resonator-heavy superconducting quantum architectures with ultra-high quality factors.

arXiv:2606.10719 [quant-ph]

(or arXiv:2606.10719v1 [quant-ph] for this version)

https://doi.org/10.48550/arXiv.2606.10719 arXiv-issued DOI via DataCite (pending registration)