Inkjet‐Printed High‐Q Nanocrystalline Diamond Resonators

Abstract

switches for wireless communication systems, as it promises high operating frequency in the GHz range, as well as narrow bandwidth (high Q-factor) and low phase noise. [1][2][3] This is thanks to diamond's excellent material properties, such as high Young's modulus (up to ≈10 6 N mm −2 ), high acoustic velocity (≈1.8 × 10 4 m s −1 ), [3] low thermoelastic damping, high thermal conductivity (>2000 W m −1 K −1 ), and low thermal expansion coefficient (≈10 −6 K −1 at 300 K). [4] The feasibility of using NCD for high-performance MEMS resonators has already been demonstrated in a range of devices, including cantilever beams, [5,6] tuning forks, [7] rings, [8] disks, [9][10][11] and spheres. [12] In particular, NCD MEMS structures that resonate with whispering gallery modes (WGM), such as disks and spheres, have shown much lower anchor losses and higher (f 0 × Q) figure of merit. [3,11] However, despite the recent progress, adding diamond structures into integrated circuits for a complete functional device remains a challenge. The current limitations relate to the difficulty in combining NCD with other microfabricated structures, mostly due to nanodiamond seeding requirements, but also due to the harsh environment during chemical vapor deposition (CVD) of the NCD film, as well as mechanical issues caused by intrinsic stress in the film. [13] Nanodiamond seeding in particular suffers from the process not being selective, i.e., instead of diamond being deposited and grown only where it is required on the device, most established methods consist of dispersing nanodiamond over a large substrate by, e.g., dip-coating, dropcasting, or spin-seeding, prior to film growth by CVD. [14] The grown NCD film needs then to be patterned by traditional photo-/e-beam lithography and lift-off techniques, which add substantial complexity and cost of fabrication. As a solution to circumvent low seeding density and plasma uniformity issues during growth of the NCD layer, Lebedev et al. proposed waferto-wafer bonding of pregrown NCD films onto another wafer to fabricate NCD disk resonators with high Q-factors (i.e., Q > 10 3 ). [9] This technique however did not remove the need to pattern the diamond after it was bonded onto the wafer. Possas et al. demonstrated the fabrication of NCD cantilever beams by patterning the nanodiamond seeding layer by means of sacrificial metal layer and etching, [15] but still top-down patterning by lithography was required. Akgul et al. reported Q-factors of the order of 7 × 10 4 for on-chip NCD disk resonators which required up to five masking/etching steps. [11] Yang et al., on the Diamond is a highly desirable material for state-of-the-art micro-electromechanical (MEMS) devices, radio-frequency filters and mass sensors, due to its extreme properties and robustness. However, the fabrication/integra tion of diamond structures into Si-based components remain costly and complex. In this work, a lithography-free, low-cost method is introduced to fabricate diamond-based micro-resonators: a modified home/office d...

Nucleation of diamond films on heterogeneous substrates: a review

“…The nanoseeding technique is now being routinely used to grow diamond on ceramics, 105,106 cutting tools [107][108][109][110] etc. Researchers have also used ND solutions for selective seeding using ink-jet style writing technology, [111][112][113][114] contact printing, 115 photolithography [116][117][118] or masking 116,119,120 to dene diamond structures without post diamond growth lithography and etching. The size dependence of the seed solution has also been investigate by some groups.…”

The Recent Progress of MEMS/NEMS Resonators

“…SiC material has excellent thermal conductivity, excessively high elastic modulus, and chemical inertness [ 14 ]. Nanocrystalline diamonds are ideal materials for manufacturing various microelectromechanical devices and mass sensors due to their high-frequency working range and excellent material properties [ 24 ].…”

“…Due to the three-dimensional structure, the symmetry is much improved, and the quality factor of more than 10 million can be achieved [ 22 ]. Microdisks, drums, and ring resonators can be used for octave frequency tuning [ 23 ], mass sensing [ 24 ], and gyroscopes [ 25 ]. The microdisk resonator uses a pedestal to support the microdisk to suspend.…”

Advanced real-time recordings of neuronal activity with tailored patch pipettes, diamond multi-electrode arrays and electrochromic voltage-sensitive dyes

“…An innovative solution is inkjet printing [98], where droplets of ND-based ink are directly deposited in specific places. The next step concerns the growth of the diamond layer by means of microwave plasma or hot-filament chemical vapour deposition: these techniques are based on the ionization of carbon precursors, provided by a flow of a gas mixture of H and > 1% CH 4 .…”