Skip to main content
U.S. flag

An official website of the United States government

Official websites use .gov
A .gov website belongs to an official government organization in the United States.

Secure .gov websites use HTTPS
A lock ( ) or https:// means you’ve safely connected to the .gov website. Share sensitive information only on official, secure websites.

Pore Size Distributions in Low-K Dielectric Thin Films From X-Ray Porosimetry



Hae-Jeong Lee, Christopher L. Soles, Da-Wei Liu, Barry J. Bauer, Wen-Li Wu


X-ray reflectivity has been used to determine the mass uptake of probe molecules in porous thin films supported on thick silicon wafers. The adsorption occurs by capillary condensation when the films are exposed to probe vapor at controlled partial vapor pressures. The probe solvent partial pressure is varied by mixing saturated air and dry air at constant temperature, or by changing sample temperature at a constant vapor concentration. Pore size distribution in the films can be calculated from the probe uptake by using typical porosimetry approaches such as by the application of the Kelvin equation to convert partial pressure into pore size. For illustration, the pore size distribution of three different nanoporous thin films, the primary candidate of ultra-low k interlevel dielectrics in the next generation of IC chips, was determined using this technique. These samples represent different generations of low-k dielectrics developed by industry.
Journal of Polymer Science Part B-Polymer Physics
No. 19


low-key dielectric, porosimetry, porosity, porous thin film, scattering, small angle neutron, x-ray reflectivity


Lee, H. , Soles, C. , Liu, D. , Bauer, B. and Wu, W. (2002), Pore Size Distributions in Low-K Dielectric Thin Films From X-Ray Porosimetry, Journal of Polymer Science Part B-Polymer Physics, [online], (Accessed July 21, 2024)


If you have any questions about this publication or are having problems accessing it, please contact

Created October 1, 2002, Updated June 2, 2021