X-ray porosimetry is developed as a technique for characterizing the pore structure in thin, low dielectric constant films supported on a silicon wafer. X-ray reflectivity is used to track the porous film density and thickness as organic vapors condensed inside the nanometer sized pores. Condensation of the organic liquid inside the film results in an appreciable density change, especially relative to the absolute mass or pressure change, that allow one to easily calculate the volume condensed liquid, and the thus the pore volume. By gradually increasing the partial pressure of the toluene, the critical radius for capillary condensation can be increase, thereby probing larger pore sizes. This allow us to extract pore size distributions from the thin, low dielectric constant films.
Citation: Special Publication (NIST SP) -
NIST Pub Series: Special Publication (NIST SP)
Pub Type: NIST Pubs
adsorption, capillary condensation, desorption, low-k dielectric, porosity, thin films, X-Ray porosimetry, X-Ray reflectivity