Pore Size Distributions in Low-k Thin Films by X-Ray Reflectivity and Small Angle Neutron Scattering

Published

October 16, 2008

Author(s)

Barry J. Bauer, Hae-Jeong Lee, R C. Hedden, Da-Wei Liu, Wen-Li Wu

Abstract

New methods have been developed to measure of pore size distributions in 1 mm films deposited on silicon wafers. Specular x-ray reflectivity (SXR) and small angle neutron scattering (SANS) have been carried out on samples surrounded by a controlled partial pressure of toluene vapor. As the vapor pressure increases, increasingly larger pores become filled with toluene liquid and SXR is used to measure the amount adsorbed as a function of pressure. The Kelvin equation can be used to calculate the pore size distributions from the adsorption data. SANS is carried out in various mixtures of saturated toluene and toluene-d8 in air. The SANS signal goes through a minimum at a toluene/toluene?d8 ratio which is the match point at which time the wall material is matched by the toluene mixture. The wall density can be calculated from this composition directly, without assuming any particular morphology type. The match point mixture is then used to fill the pores at various partial pressures and SANS of these samples provides an independent measure of pore size distribution.

Citation

Pore Size Distributions in Low-k Thin Films by X-Ray Reflectivity and Small Angle Neutron Scattering

Pub Type

Others

Keywords

porosimetry, porrosity, reflectivity, SANS, thin film, x-ray

Citation

Bauer, B. , Lee, H. , Hedden, R. , Liu, D. and Wu, W. (2008), Pore Size Distributions in Low-k Thin Films by X-Ray Reflectivity and Small Angle Neutron Scattering, Pore Size Distributions in Low-k Thin Films by X-Ray Reflectivity and Small Angle Neutron Scattering (Accessed October 22, 2025)