X-Ray Reflectivity as a Metrology to Characterize Pore Size Distributions in Low-K Dielectric Films

Published

August 1, 2002

Author(s)

V. J. Lee, Christopher Soles, D W. Liu, Barry J. Bauer, Wen-Li Wu

Abstract

A methodology is described whereby we use specular x-ray reflectivity to characterize the pore size distributions in porous low-K dielectric films. X-ray reflectivity provides a sensitive measure of the density (and thus porosity) in a thin, low-K dielectric film. When these reflectivity experiments are done in the presence of toluene vapor, the phenomenon of capillary condensation can be used to extract the pore size distribution in the film. Condensation of the toluene inside a pore will effectively increase the average density of the film. From the Kelvin equation, we know that there is a critical radius at which the solvent vapor will spontaneously condense inside the pores, and this radius changes with the partial pressure. So by varying the partial pressure and monitoring the change in the film density, we can map out the pore size distributions in sub-micron thick low-K dielectric films.

Citation

Polymer Preprints

Volume

87

Pub Type

Journals

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Keywords

low-k dielectric films, pore size distribution, porosimetry, x-ray reflectivity

Citation

Lee, V. , Soles, C. , Liu, D. , Bauer, B. and Wu, W. (2002), X-Ray Reflectivity as a Metrology to Characterize Pore Size Distributions in Low-K Dielectric Films, Polymer Preprints, [online], https://tsapps.nist.gov/publication/get_pdf.cfm?pub_id=852038 (Accessed October 26, 2025)