A New Small Angle X-ray Scattering Technique for Determining Nano-scale Pore/particle Size Distributions in Thin Film

We have developed a new Small Angle X-ray Scattering (SAXS) technique by use of reflection geometry for determining particle / pore size distribution in thin film. In order to avoid strong specular reflection, we used offset scan (2θ / θ+δθ) for measuring scattering data. To deal with reflection and refraction at surface and interfaces, we calculated X-ray wave field in the film based on Distorted Wave Born Approximation (DWBA) [1]. We assume the particle / pore size distribution follows Γ-distribution function, and optimized the parameters of distribution by non-liner least square method comparing simulated and experimental data. We applied the present X-ray scattering technique to pore size analysis in porous low dielectric films on Si substrates. The results of X-ray technique agreed fairly well with those of gas adsorption and TEM techniques.