Strain Effects in a Directly Bonded Diamond-on-Insulator Substrate
Ioannis Varveris (TU Delft - Electrical Engineering, Mathematics and Computer Science)
Gianni D. Aliberti (TU Delft - QID/Ishihara Lab)
Tianyin Chen (TU Delft - Electrical Engineering, Mathematics and Computer Science)
Filip A. Sfetcu (Student TU Delft)
Diederik J.W. Dekker (Student TU Delft)
Alfred Schuurmans (Student TU Delft)
Nikolaj K. Nitzsche (TU Delft - Electrical Engineering, Mathematics and Computer Science, TU Delft - Electrical Engineering, Mathematics and Computer Science)
Salahuddin Nur (TU Delft - Electrical Engineering, Mathematics and Computer Science, TU Delft - Electrical Engineering, Mathematics and Computer Science)
Ryoichi Ishihara (TU Delft - QID/Ishihara Lab, TU Delft - Electrical Engineering, Mathematics and Computer Science, TU Delft - Electrical Engineering, Mathematics and Computer Science)
More Info
expand_more
Other than for strictly personal use, it is not permitted to download, forward or distribute the text or part of it, without the consent of the author(s) and/or copyright holder(s), unless the work is under an open content license such as Creative Commons.
Abstract
The direct bonding process of a diamond-on-insulator (DOI) substrate enables monolithic integration of diamond photonic structures for quantum computing by improving photon collection efficiency and entanglement generation rate between emitters. It also addresses key fabrication challenges, such as robustness, bonding strength, and scalability. This study investigates strain effects in DOI substrates following direct bonding. Strain generation is expected near the diamond–SiO2/Si interface due to the thermal expansion coefficient mismatch between the bonded materials. Strain-induced lattice distortions are characterized using nitrogen-vacancy (NV) centers in diamond via optically detected magnetic resonance (ODMR) and photoluminescence (PL) mapping. PL mapping reveals interference fringes in unbonded regions, indicating bonding irregularities. Depth-resolved ODMR measurements show a volumetric strain component increase of ≈0.45 MHz and a shear component increase of ≈0.71 MHz between the top surface and the DOI interface. However, ODMR signal contrast and peak linewidth remain largely unaffected, suggesting no visible deterioration in the optical properties of the emitters. By combining ODMR and PL mapping, this work establishes a robust methodology for assessing bonding quality and strain impact on NV centers, an essential step toward advancing scalable quantum technologies and integrated photonic circuits.