X-ray and neutron porosimetry as powerful methodologies for determining structural characteristics of porous low-k thin films

Methylsilsesquioxane based porous low-k dielectric films with varying porogen loading have been characterized using X-ray and neuron porosimetry to determine their pore size distribution, average density, wall density, porosity, density profiles, and porosity profiles. The porosity and the average pore size of the sample with 45% porogen were 52% and 23 /spl Aring/ in radius, respectively. Pore size, was consistent with that from small angle neutron scattering measurements. The wall density was found to be independent of the porogen content and it appeared that the porogen was 100% effective in generating pores.