Statistical analysis of topographic images of nanoporous silicon and model surfaces

We investigated the quantitative description of nanoporous silicon morphology and its correlation with electrical and optical properties. We performed first-order as well as second-order statistical analysis of AFM images of nanoporous silicon fabricated by two different methods: reaction-induced-vapor-phase-stain-etch and electrochemical. We also simulated AFM images by generation of various model surfaces. From the height–height correlation plots, we were able to observe the effects of the growth method on RMS roughness parameter and verify that photoluminescence can be observed despite very small changes in silicon surface morphology. The analysis of the model surfaces showed that it is possible to reproduce the self-affine character of the porous surfaces by means of a linear combination of sine surfaces. q 2005 Elsevier Ltd. All rights reserved.