Thermal conductivity of thick meso-porous silicon layers by micro-Raman scattering

We report here a theoretical model describing specific mechanisms of heat t ransport in as-prepared and oxidized meso-porous silicon layers. The model is in good agreement with experimental measurements performed by micro-Rama n scattering on the layers surface. For the first time, thermal conductivit y inhomogeneity along the porous layer thickness of 100 mu m is studied. Di rect correlation between the thermal conductivity and morphology variations along the layer thickness is brought to the fore. A new approach to estima te local porosity of the porous layers based on thermal conductivity and Si nanocrystallite size measurements is also proposed. (C) 1999 American Inst itute of Physics. [S0021-8979(99)08124-4].