AVS 59th Annual International Symposium and Exhibition
    MEMS and NEMS Monday Sessions
       Session MN-MoA

Invited Paper MN-MoA1
Acute Stress in Silicon Nitride

Monday, October 29, 2012, 2:00 pm, Room 10

Session: Multi-scale Interactions of Materials and Fabrication at the Micro- and Nano-scale
Presenter: J.M. Parpia, Cornell University
Authors: J.M. Parpia, Cornell University
V.P. Adiga, Cornell University
B. Ilic, Cornell University
R.A. Barton, Cornell University
R. De Alba, Cornell University
I. Wilson-Rae, Technische Universität München, Germany
H.G. Craighead, Cornell University
Correspondent: Click to Email
Mechanical structures fabricated from highly stressed silicon nitride films exhibit some of the highest Q (Quality factor) values observed in MEMS/NEMS structures at room temperatures. By varying the diameter and thickness of high stress silicon nitride circular "drum" structures, we observe that the dissipation follows generally predictable behaviors. Qualitatively we see that the fundamental out-of-plane resonance mode has the lowest Q in large structures (though it can still exceed 105). As higher modes with radial nodal lines (described as cake like modes) are added, the Q increases. Modes that add a nodal line at a constant radius also have higher Qs, but the Q improvement over the fundamental is not large, and can also lead to lowering of the Q in small structures. Generally thinner more uniform cross section structures reveal the higher Qs. As higher order resonances are excited, the product of the frequency times Q (fQ) tends to a constant. Many of these behaviors are consistent with recent models. This presentation will describe the results obtained as the diameter and thickness of the devices of these structures was varied.