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Fracture Strength of Polycrystalline Silicon

Published online by Cambridge University Press:  10 February 2011

P.T. Jonestt ,
G.C. Johnsontt  and
R.T. Howe
P.T. Jonestt
Affiliation:
Berkeley Sensor & Actuator Center, University of California, Berkeley, CA 94720 Department of Mechanical Engineering, University of California, Berkeley, CA 94720
G.C. Johnsontt
Affiliation:
Berkeley Sensor & Actuator Center, University of California, Berkeley, CA 94720 Department of Mechanical Engineering, University of California, Berkeley, CA 94720
R.T. Howe
Affiliation:
Berkeley Sensor & Actuator Center, University of California, Berkeley, CA 94720 Department of Mechanical Engineering, University of California, Berkeley, CA 94720 Department of Electrical Engineering and Computer Sciences, University of California, Berkeley, CA 94720
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Abstract

A structure has been developed to measure the fracture strength of thin films that allows for a large amount of statistical data to be generated from a single die. The strength of a material is determined by measuring the displacement at fracture of cantilever beams bending in-plane. This device has been used to measure the fracture strain of three different polysilicon materials: polysilicon from two different MCNC MUMPS runs and a polysilicon fabricated at the Microfabrication Laboratory at the University of California at Berkeley. The strain at fracture of the MUMPS polysilicon was measured to be 1.5% ± 0.2% for both MCNC MUMPS runs. The Berkeley polysilicon exhibited a fracture strength of 1.2% ± 0.1%, a difference from the MUMPS result that is statistically significant. Also, no statistical difference in fracture strength was measured on specimens that were super-critically carbon dioxide dried as opposed to furnace dried. In a separate experiment, the Young's modulus of the MCNC MUMPS polysilicon was found to be 173 ± 20 GPa.

Type
Research Article
Information
MRS Online Proceedings Library (OPL) , Volume 518: Symposium N – Microelectromechanical Structures for Materials Research , 1998 , 197
Copyright
Copyright © Materials Research Society 1998

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References

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