Superconducting Through-Substrate Vias on Sapphire Substrates for Quantum Circuits

Autor: Kiyotaka Mukasa, Yusuke Nuruki, Hayato Kubo, Yoshihide Narahara, Motohiro Umehara, Kazuyuki Fujie
Jazyk: angličtina
Rok vydání: 2024
Předmět:
Zdroj: IEEE Transactions on Quantum Engineering, Vol 5, Pp 1-4 (2024)
Druh dokumentu: article
ISSN: 2689-1808
DOI: 10.1109/TQE.2024.3416963
Popis: Sapphire substrates have recently been recognized for their potential to improve the coherence time of superconducting qubits. However, due to challenges in via fabrication, silicon substrates have been predominantly used for qubits. In this study, we fabricated vias on sapphire substrates using lasers and deposited TiN films by chemical vapor deposition. Cross-sectional views of the via confirmed uniform thickness of the TiN film along the via wall. In addition, the TiN film exhibited a superconducting transition at 4.5 K, demonstrating the successful deposition of a high-quality homogeneous superconducting film. This represents the first example of realizing superconducting through-substrate vias on sapphire substrates, a crucial first step toward achieving the 3-D integration of qubits while maintaining coherence time.
Databáze: Directory of Open Access Journals