Characterization of porous low-k dielectric thin films using X-ray reflectivity, small angle neutron scattering and ion scattering

A novel methodology using a combination of high energy ion scattering, X-ray reflectivity, and small angle neutron scattering is used to characterize the structure and properties of porous low-k dielectric films after varying process conditions. From these techniques we determine the film thickness, average electron density, and density depth profile, wall density, porosity, average pore size, and pore connectivity. When the dielectric constant increases from 1.5 to 2.2, the relative wall density increases by approximately 25% and relative decreases in the volume fraction of porosity and the average pore size are approximately 10% and 50%, respectively.