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

Published online by Cambridge University Press:  10 February 2011

H. Kahn ,
N. Tayebi ,
R. Ballarini ,
R.L. Mullen  and
A.H. Heuer
H. Kahn
Affiliation:
Department of Materials Science and Engineering, Case Western Reserve University, Cleveland, Ohio
N. Tayebi
Affiliation:
Department of Mechanical and Aerospace Engineering, Case Western Reserve University, Cleveland, Ohio
R. Ballarini
Affiliation:
Department of Civil Enginering, Case Western Reserve University, Cleveland, Ohio
R.L. Mullen
Affiliation:
Department of Civil Enginering, Case Western Reserve University, Cleveland, Ohio
A.H. Heuer
Affiliation:
Department of Materials Science and Engineering, Case Western Reserve University, Cleveland, Ohio
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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.

Type
Research Article
Information
MRS Online Proceedings Library (OPL) , Volume 605: Symposium MM – Materials Science of Microelectromechanical Systems Devices II , 1999 , 25
Copyright
Copyright © Materials Research Society 2000

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