Static and dynamic determination of the mechanical properties of nanocrystalline diamond micromachined structures

We present the static and dynamic mechanical characterization of several nanocrystalline diamond (NCD) freestanding micromachined structures. NCD films, fabricated by microwave plasma chemical vapour deposition on silicon (1 0 0), were underetched in order to release the test structures. Two different techniques are combined for the mechanical characterization, atomic force microscopy (AFM) and magnetomotive resonant frequency spectroscopy. The static Young's modulus (E) of the micromachined structures was calculated from the AFM measurements, resulting in E = 947 ± 40 GPa. This value is in excellent agreement with the determination of an acoustic velocity of 17 283 ± 232 m s?1, calculated from the resonance frequency of double-clamped structures and coupled single-clamped U-frame resonators.