A Young's modulus study of n-And p-type porous silicon

Abstract

With the number of MEMS based applications utilizing porous silicon increasing, it has become more important to know the mechanical properties of the material. Using nanoindentation, the Young's modulus of various n-type and p-type mesoporous silicon samples has been measured. The porous silicon samples were produced by electrochemical anodization in an ethanoic hydrofluoric acid solution. Anodization conditions were varied to study the impact on Young's modulus due to porosity and pore morphology. The current densities of the p-type samples were varied between 20 mA/cm 2 and 60 mA/cm 2 and the n-type samples current densities were varied between 3 mA/cm 2 and 60 mA/cm 2. The investigation demonstrated a strong morphological change for n-type samples which caused a much broader range of Young's modulus values measured. It was also observed that the p-type samples pore morphologies did not significantly change over the range of current densities used, therefore the changes in the Young's modulus can be attributed to a change in porosity. © 2009 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.