| AVS 62nd International Symposium & Exhibition | |
| MEMS and NEMS | Thursday Sessions |
| Session MN-ThM |
| Session: | Atomic Layer Nanostructures and 2D NEMS |
| Presenter: | Xu-Qian Zheng, Case Western Reserve University |
| Authors: | X.-Q. Zheng, Case Western Reserve University J. Lee, Case Western Reserve University P.X.-L. Feng, Case Western Reserve University |
| Correspondent: | Click to Email |
Among recently emerged two-dimensional (2D) materials, hexagonal boron nitride (h-BN) possesses some unique properties, including a wide bandgap (5.9eV) [1] and electrical insulation, excellent thermal stability, and superb inertness [2]. It also has very high elastic modulus (EY ~810GPa) which is on the same order with that of graphene [3]. Similar to graphene, h-BN also has very high fracture strain limits [4] that are far beyond achievable values in conventional 3D crystals. In particular, h-BN offers piezoelectricity in an ultrathin 2D platform [5]. Therefore h-BN is an attractive structural material for 2D nanoelectromechanical systems (NEMS), especially as resonant transducers in harsh environment applications.
In this work, we describe the construction of h-BN drumhead structures and the first demonstration of vibrating h-BN 2D NEMS resonators. We investigate the elastic properties and resonant characteristics of such devices, by measuring flexural-mode resonances using ultrasensitive laser interferometry. We first fabricate circular drumhead h-BN resonators with thickness ranging from 9nm to 292nm and diameter of ~10μm using a completely dry transfer technique [6]. Then, by conducting both undriven and driven measurements on h-BN resonators, we observe and study the multimode resonances up to 7 modes, in high frequency (HF) and very high frequency (VHF) range. We further conduct spatially resolved measurements to attain the mode shapes of the multimode resonances. We then investigate the multimode frequency scaling of h-BN nanomechanical resonators with different thickness and analyze the experimental results to extract the elastic properties, structural and geometric effects. Finally, in comparison with the previously studied graphene and MoS2 2D NEMS resonators, we identify potential applications of these new h-BN devices in the 2D NEMS family.
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[3] C. Lee, et al., Science 321, 385-388 (2008).
[4] L. Song, et al., Nano Lett. 10, 3209-3215 (2010).
[5] K.-A. Duerloo, et al., J. Phys. Chem. Lett. 3, 2871-2876 (2012).
[6] R. Yang, et al., J. Vac. Sci. & Tech. B 32, 061203 (2014).