Structural Characterization of a Porous Low Dielectric Constant Thin Film With a Non Uniform Depth Profile

Published

July 1, 2002

Author(s)

Eric K. Lin, V. J. Lee, G W. Lynn, Wen-Li Wu, M L. O'Neill

Abstract

High resolution x-ray reflectivity (XR) and small angle neutron scattering (SANS) are applied to characterize both the non-uniform depth profile and pore structure of a low dielectric constant (low k) thin film as prepared on a silicon substrate. The XR data show that the density depth profile has a multilayered structure with a dense, nonporous top layer and a less dense, porous layer. A scattering invariant analysis of the SANS data is used to determine the average chord length of the pores, (14.8 2.0) nm, independent of the depth profile. Given the elemental composition of the film, the XR and SANS data are combined to calculate the mass density of the top layer (1.13 0.05) g/cm³, the porosity of the less dense layer (0.28 0.10) g/cm³, and the wall density (0.92 0.15) g/cm³.

Citation

Applied Physics Letters

Volume

81

Issue

No. 4

Pub Type

Journals

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Keywords

pore size, porosity, porous low-k dielectric, small angle neutron scattering, x-ray reflectivity

Citation

Lin, E. , Lee, V. , Lynn, G. , Wu, W. and O'Neill, M. (2002), Structural Characterization of a Porous Low Dielectric Constant Thin Film With a Non Uniform Depth Profile, Applied Physics Letters, [online], https://tsapps.nist.gov/publication/get_pdf.cfm?pub_id=851997 (Accessed October 9, 2025)