Digital Repository, ICF12, Ottawa 2009

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The Impact of Sidewall Roughness on the Macroscopic Strength of Polycrystalline Silicon
J.W. Foulk III, B.L. Boyce, E.D. Reedy Jr.

Last modified: 2013-05-07


In order to design efficient, reliable microelectromechanical systems (MEMS),one must understand the statistics of failure. For brittle systems, we can betterunderstand strength distributions through flaw distributions. Specifically, we seekto investigate the role of sidewall flaw size, shape, and spacing on the strength ofpolycrystalline silicon. Although the deleterious effects of sidewall roughness arewell accepted and recent studies have illustrated marked improvements throughreduced roughness, most studies have focused on the long crack toughness andthe macroscopic strength of polycrystalline silicon. Based on results from atomicforce microscopy and transmission electron microscopy, we seek toparameterize the sidewall flaw size, shape, and spacing. Idealized, twodimensionalfinite element models of MEMS tensile specimens will be employedto determine the sensitivity of flaw parameters. Through these initial, fundamentalstudies, we hope to better understand the role of defect distributions on thevariation in the macroscopic strength of polycrystalline silicon.

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