| AVS 58th Annual International Symposium and Exhibition | |
| MEMS and NEMS Group | Thursday Sessions |
| Session MN-ThA |
| Session: | Multi-scale Interactions of Materials and Fabrication at the Micro- and Nano-scale |
| Presenter: | Vivekananda Adiga, Cornell University |
| Authors: | V.P. Adiga, Cornell University R.B. Ilic, Cornell University R.A. Barton, Cornell University I. Wilson-Rae, Technische Universität München, Germany H.G. Craighead, Cornell University J.M. Parpia, Cornell University |
| Correspondent: | Click to Email |
We have fabricated up to 1 mm diameter high tensile stress (1.2 GPa) circular SiN membranes. Stoichiometric amorphous high tensile stress SiN is a useful material for nanomechanical devices and resonators made from it have shown extremely high Q (> 1,000,000) at room temperature.1 We used both optical and electron beam lithography to define circular structures and measured their resonant frequency and Q using optical interferometric detection methods. The measured mechanical Q shows a strong modal dependence, indicating the influence of clamping losses. Azimuthal harmonics of circular resonators with diameter s> 200 mm show an exponential drop in dissipation within an individual modal family (n = 1,2,3.., m) apparently due to the destructive interference between the waves radiated by adjacent sections of periphery.2 However, still higher order modes of large resonators and modes of smaller resonators are strongly influenced by a characteristic fQ limit of 2 × 1013 possibly indicating the presence of intrinsic dissipation in the high frequency limit. These findings pave the way for identifying optimum high Q modes of stressed oscillators for applications in mass sensing and fundamental research in optomechanics.
1) D. Southworth et al, PRL, 2009
2) I. Wilson-Rae et al PRL, 2011