Surface-activated direct bonding of diamond (100) and c-plane sapphire with high transparency for quantum applications

Journal article (2023)

Authors

T. Miyatake Fujitsu Limited
Kenichi Kawaguchi Fujitsu Limited
Manabu Ohtomo Fujitsu Limited
Toshiki Iwai Fujitsu Limited
Tetsuro Ishiguro Fujitsu Limited
Yoshiyasu Doi Fujitsu Limited
J. Hermias , QuTech Advanced Research Centre
S. Nur QuTech Advanced Research Centre, Quantum Circuit Architectures and Technology - EEMCS
R. Ishihara QID/Ishihara Lab - QuTech Advanced Research Centre , QuTech Advanced Research Centre, Quantum Circuit Architectures and Technology - EEMCS
Shintaro Sato Fujitsu Limited
Research Group
Quantum Circuit Architectures and Technology (EEMCS) (TU Delft)
Copyright: © 2023 Tetsuya Miyatake, Kenichi Kawaguchi, Manabu Ohtomo, Toshiki Iwai, Tetsuro Ishiguro, Yoshiyasu Doi, J. Hermias, S. Nur, R. Ishihara, Shintaro Sato
DOI: https://doi.org/10.35848/1347-4065/acf42a
More Info
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Published Date

2023

Language

English

Faculty

Electrical Engineering, Mathematics and Computer Science

Department

Quantum & Computer Engineering

Research Group

Quantum Circuit Architectures and Technology

Abstract

Surface-activated direct bonding of diamond (100) and c-plane sapphire substrates is investigated using Ar atom beam irradiation and high-pressure contact at RT. The success probability of bonding strongly depends on the surface properties, i.e, atomic smoothness for the micron-order area and global flatness for the entire substrate. Structural analysis reveals that transformation from sapphire to Al-rich amorphous layer is key to obtaining stable bonding. The beam irradiation time has optimal conditions for sufficiently strong bonding, and strong bonding with a shear strength of more than 14 MPa is successfully realized. Moreover, by evaluating the photoluminescence of nitrogen-vacancy centers in the diamond substrate, the bonding interface is confirmed to have high transparency in the visible wavelength region. These results indicate that the method used in this work is a promising fabrication platform for quantum modules using diamonds.