Title: Modelling and verification of XeF2 silicon micromachining

Authors: George Floarea, Muthukumaran Packirisamy, Ion Stiharu

Addresses: Concordia University, Department of Mechanical and Industrial Engineering, Montreal, Quebec, H3G 1M8, Canada. ' Concordia University, Department of Mechanical and Industrial Engineering, Montreal, Quebec, H3G 1M8, Canada. ' Concordia University, Department of Mechanical and Industrial Engineering, Montreal, Quebec, H3G 1M8, Canada

Abstract: In the present work, a new and computer-controlled xenon difluoride etching equipment for silicon was designed and installed. A model for the XeF2 isotropic etching of silicon based on an atomic approach and fine tuned through pressure increase in the reaction chamber, due to formation of the reaction products, is presented. The shape of the etch features is predicted by a Matlab® code, based on the developed model. The etch depth and lateral under-etch can be calculated for a given feature and the chamber loading. The effect of concave corners is ignored in the model although the experimental results indicated a slow down etch rate at such locations. Using the designed etching equipment, experiments were carried on silicon samples with square and circular mask openings in order to validate the proposed etching model. The experimental values were compared with the theoretical ones and were found to be in good agreement.

Keywords: isotropic etching; xenon difluoride; MEMS; etching model; silicon micromachining; nanomanufacturing; microelectromechanical systems; etch depth; lateral under-etch.

DOI: 10.1504/IJNM.2009.027051

International Journal of Nanomanufacturing, 2009 Vol.3 No.1/2, pp.55 -72

Published online: 13 Jul 2009 *

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