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Strength and fracture of Si micropillars: A new scanning electron microscopy-based micro-compression test

Published online by Cambridge University Press:  03 March 2011

B. Moser ,
K. Wasmer ,
L. Barbieri  and
J. Michler
B. Moser*
Affiliation:
EMPA Thun, Swiss Federal Institute for Materials Testing and Research, Laboratory for Materials Technology, 3602 Thun, Switzerland
K. Wasmer
Affiliation:
EMPA Thun, Swiss Federal Institute for Materials Testing and Research, Laboratory for Materials Technology, 3602 Thun, Switzerland
L. Barbieri
Affiliation:
Advanced Photonics Laboratory, Swiss Federal Institute of Technology EPFL, 1015 Lausanne, Switzerland
J. Michler
Affiliation:
EMPA Thun, Swiss Federal Institute for Materials Testing and Research, Laboratory for Materials Technology, 3602 Thun, Switzerland
*
a) Address all correspondence to this author. e-mail: benedikt.moser@alumni.ethz.ch
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Abstract

A novel method for in situ scanning electron microscope (SEM) micro-compression tests is presented. The direct SEM observation during the instrumented compression testing allows for very efficient positioning and assessment of the failure mechanism. Compression tests on micromachined Si pillars with volumes down to 2 μm3 are performed inside the SEM, and the results demonstrate the potential of the method. In situ observation shows that small diameter pillars tend to buckle while larger ones tend to crack before failure. Compressive strength increases with decreasing pillar diameter and reaches almost 9 GPa for submicrometer diameter pillars. This result is in agreement with earlier bending experiments on Si. Difficulties associated with precise strain measurements are discussed.

Keywords

Scanning electron microscopy (SEM)SiStrength
Type
Articles
Information
Journal of Materials Research , Volume 22 , Issue 4 , April 2007 , pp. 1004 - 1011
Copyright
Copyright © Materials Research Society 2007

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