Authors: I. De Vlaminck, K. De Greve, R. Naulaerts, V. Sivasubramaniam, L. Lagae, H.A.C. Tilmans and G. Borghs
Affilation: IMEC, Belgium
Pages: 297 - 300
Keywords: nems, mass sensing, diabolo cross-section, mass detection limit
A new method for improving the mass detection limit of nanomechanical resonators in crystalline silicon, compatible with scaling, is demonstrated. Clamped-clamped silicon beam resonators are fabricated with a non-rectangular, ‘diabolo’ cross-section starting from SOI wafers. The simple, single mask process for making these resonators is demonstrated. The non-conventional cross-section results in a change of almost all functional parameters, frequency, effective mass, and signal to noise ratio, thereby decreasing the mass detection limit of the resonator up to a factor of 2.7 as compared to similar devices without the additional step. A comparison between beams with a rectangular cross-section and beams with the novel diabolo cross-section by finite element modeling confirms the predictions on frequency gain made by the analytical model. First experimental results on resonators with a rectangular and diabolo cross-section confirm the predictions made by modeling.