Fractal analysis was applied to images of rough silicon surfaces which were acquired with an atomic force microscope. Spectroscopic ellipsometry was also used to extract roughness information using an optical model and the Bruggeman effective-medium approximation. Different rough silicon surfaces were examined from three microelectronics processes; rapid thermal chemical vapor deposition, chemical etching, and thermal oxidation. The fractal nature of the surfaces and the correlation between fractal, optical, and topographic parameters were explored.