Open Access Nano Express

Mechanical properties of sintered meso-porous silicon: a numerical model

Roberto Martini12*, Valerie Depauw2, Mario Gonzalez2, Kris Vanstreels2, Kris Van Nieuwenhuysen2, Ivan Gordon2 and Jef Poortmans12

Author affiliations

1 , Department of Electrical Engineering (ESAT), KU Leuven, Kasteelpark 10, Leuven-Heverlee 3001, Belgium

2 , Interuniversitair Micro-Electronica Centrum (IMEC), Kapeldreef 75, Leuven-Heverlee 3001, Belgium

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Citation and License

Nanoscale Research Letters 2012, 7:597  doi:10.1186/1556-276X-7-597

Published: 29 October 2012

Abstract

Because of its optical and electrical properties, large surfaces, and compatibility with standard silicon processes, porous silicon is a very interesting material in photovoltaic and microelectromechanical systems technology. In some applications, porous silicon is annealed at high temperature and, consequently, the cylindrical pores that are generated by anodization or stain etching reorganize into randomly distributed closed sphere-like pores. Although the design of devices which involve this material needs an accurate evaluation of its mechanical properties, only few researchers have studied the mechanical properties of porous silicon, and no data are nowadays available on the mechanical properties of sintered porous silicon. In this work we propose a finite element model to estimate the mechanical properties of sintered meso-porous silicon. The model has been employed to study the dependence of the Young’s modulus and the shear modulus (upper and lower bounds) on the porosity for porosities between 0% to 40%. Interpolation functions for the Young’s modulus and shear modulus have been obtained, and the results show good agreement with the data reported for other porous media. A Monte Carlo simulation has also been employed to study the effect of the actual microstructure on the mechanical properties.

Keywords:
Porous silicon; Homogenization; Irregular microstructure; Finite element method