Abstract: A method and apparatus for evaluation of films, such as low-k thin films with nano-scale pores, are provided. The evaluation may include characterization of the pore structure, the characterization results in determining pore sizes, hence obtaining pore size data. Moreover, the characterization may result in a non-destructive evaluation of mechanical properties, in particular the Young's Modulus, or the effect of interfering physical & chemical factors such as Pore Killers. Further, in line monitoring or studying of pore structure porosity and pore size distribution (PSD) of low-k films and evaluation of the mechanical properties of porous low-k films simultaneously using the same set of experimental data is provided.