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Wafer-Level Strength and Fracture Toughness Testing of Surface-Micromachined MEMS Devices

  • H. Kahn (a1), N. Tayebi (a2), R. Ballarini (a3), R.L. Mullen (a3) and A.H. Heuer (a1)...

Abstract

Determination of the mechanical properties of MEMS (microelectromechanical systems) materials is necessary for accurate device design and reliability prediction. This is most unambiguously performed using MEMS-fabricated test specimens and MEMS loading devices. We describe here a wafer-level technique for measuring the bend strength, fracture toughness, and tensile strength of MEMS materials. The bend strengths of surface-micromachined polysilicon, amorphous silicon, and polycrystalline 3C SiC are 5.1±1.0, 10.1±2.0, and 9.0±1.0 GPa, respectively. The fracture toughness of undoped and P-doped polysilicon is 1.2±0.2 MPa√m, and the tensile strength of polycrystalline 3C SiC is 3.2±1.2 GPa. These results include the first report of the mechanical strength of micromachined polycrystalline 3C SiC.

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Wafer-Level Strength and Fracture Toughness Testing of Surface-Micromachined MEMS Devices

  • H. Kahn (a1), N. Tayebi (a2), R. Ballarini (a3), R.L. Mullen (a3) and A.H. Heuer (a1)...

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