Diamond disk micro-electro-mechanical transducers, CDISK
Electronic Semiconductors, Components and Circuits, Integrated Systems, Sensor Technology, Theoretical Electrical Engineering
Synthesis and Properties of Functional Materials
Mechanical Properties of Metallic Materials and their Microstructural Origins
Final Report Abstract
High hardness microelectromechanical devices made of nanocrystalline diamond (NCD) are interesting candidates for on-chip resonators with a high quality factor (Q) and high resonance frequencies (f), which can be used to demonstrate energy efficient frequency filters with applications in mobile communication systems. In particular, disk resonators that vibrate in whispering gallery modes (WGMs) can achieve very high (fxQ) values due to their low armature loss. The disadvantage of these resonators is their small oscillation amplitude, which is caused by the low electrostatic interaction between the stimulating electrode and the resonator. For this reason, the C-DISK project investigated an alternative excitation of high-frequency, mechanical vibrations of disk resonators using piezoelectric AlN films. As part of CDISK, the maximum deflections of the resonators were simulated by FEM COMSOL and their design have been optimized towards improved oscillation amplitude. Our choice to focus on disk resonators with piezoelectric excitation was mainly motivated by the high simulated fxk2 parameters and the possibility of increasing the Qxf values by using the "suspended electrode" system. Disk resonators with optimized layout made of NCD:B (“capacitive” resonator) and on AlN/NCD:B structures (“piezoelectric” resonators) were processed. In the project, the complex optimization of resonator design, the thin film deposition, the process technology together with the characterization of the heterostructures and finally the resonator components were implemented. The quality factors Q and oscillation frequencies derived by laser deflection vibrometry for the WGMs of the piezoelectric disk resonators were compared with the properties of diamond-based bridges and beams from our preliminary work. While the Q-factors for beams and bridges decrease with increasing frequency and follow a general limitation of the quality factor due to clamping losses, a simultaneous increase in quality factor and frequency was achieved by the disc resonators developed. With the chosen geometries of the disk resonators, we observed a linear increase in quality factor from 200 to 3000 together with an increase in the resonance frequency from 3 MHz to 50 MHz. The project results achieved for the material and technology development of AlN/diamond- based disc resonators have been introduced as preliminary work in a BMBF proposal for the development of high frequency filters for the mobile communication network (5G). In this project, the "down scaling" of the resonators to realize resonance frequencies of > 800 MHz is targeted in order to reach application motivated specifications of the AlN/diamond based filters.
Publications
- “Nanodiamond resonators fabricated on 8 ″Si substrates using adhesive wafer bonding,” Journal of Micromechanics and Microengineering 27 (6), 065011 (2017)
V. Lebedev, T. Lisec, T. Yoshikawa, M. Reusch, D. Iankov, C. Giese, A. Žukauskaitė, V. Cimalla and O. Ambacher
(See online at https://doi.org/10.1088/1361-6439/aa6e76) - “Temperature cross-sensitivity of AlN-based flexural plate wave sensors,” IEEE Sensors Journal 18, 7810 (2018)
M. Reusch, K. Holc, V. Lebedev, N. Kurz, A. Zukauskaite, O. Ambacher
(See online at https://doi.org/10.1109/JSEN.2018.2853644) - “Formation of icosahedron twins during initial stages of heteroepitaxial diamond nucleation and growth,” Journal of Applied Physics 125 (7), 075305 (2019)
V. Lebedev, T. Yoshikawa, C. Giese, L. Kirste, A. Žukauskaitė, A Graff, F. Meyer, F. Burmeister, O. Ambacher
(See online at https://doi.org/10.1063/1.5085184) - “Influence of substrate holder configurations on bias enhanced nucleation area for diamond heteroepitaxy: Toward wafer-scale single-crystalline diamond synthesis,” Journal of Vacuum Science & Technology B 37, 021207 (2019)
T. Yoshikawa, D. Herrling, F. Meyer, F. Burmeister, C.E. Nebel, O. Ambacher, V. Lebedev
(See online at https://doi.org/10.1116/1.5086020) - “Influence of Different Surface Morphologies on the Performance of High-Voltage, Low- Resistance Diamond Schottky Diodes”, IEEE Transactions on Electron Devices 67 (6), 2471 (2020)
P. Reinke, F. Benkhelifa, L. Kirste, H. Czap, L. Pinti, V. Zürbig, V. Cimalla, Ch. Nebel, O. Ambacher
(See online at https://doi.org/10.1109/TED.2020.2989733) - “Microstructural and optical emission properties of diamond multiply twinned particles,” Journal of Applied Physics 127 (2), 025303 (2020)
V. Lebedev, T. Yoshikawa, C. Schreyvogel, L. Kirste, J. Weippert, M. Kunzer, A. Graff, O. Ambacher
(See online at https://doi.org/10.1063/1.5127170) - “Growth defects in heteroepitaxial diamond,” Journal of Applied Physics 129 14 (2021)
V. Lebedev, J. Engels, J. Kustermann, J. Weippert, V. Cimalla, L. Kirste, Ch. Giese, P. Quellmalz, A. Graff, F. Meyer, M. Höfer, V. Sittinger
(See online at https://doi.org/10.1063/5.0045644) - „Quality Assessment of In Situ Plasma-Etched Diamond Surfaces for Chemical Vapor Deposition Overgrowth,” Phys. Status Solidi (a) 218, 2100035 (2021)
J. Langer, V. Cimalla, M. Prescher, J. Ligl, B. Tegetmeyer, C. Schreyvogel, O. Ambacher
(See online at https://doi.org/10.1002/pssa.202100035)
