The Chemical Composition of Low Dielectric Constant Films From Novel Ion Scattering Methodologies

Published

October 16, 2008

Author(s)

Christopher Soles, R J. Composto, H Wang

Abstract

A novel ion beam scattering methodology is described for determining the chemical composition of thin, Si-based low dielectric constant (k) films that typically also contain light elements like O, C, and H. Traditional elastic Rutherford backscattering spectrometry (RBS) and/or nuclear resonance enhanced RBS are not well-suited for discerning the C and O compositions in materials that also contain heavy elements like Si. To circumvent this we describe a 2 MeV forward scattering (FS) spectrometry method that greatly enhances the light element sensitivity to determine the Si:O:C ratio. Complimentary forward recoil spectrometry (FRES) experiments are used to determine the H abundance.The relative H content from the FRES spectrum of a low-k film is converted to an absolute aerial H density by comparison with a polystyrene (PS) reference film of known H content and thickness. Once the absolute aerial H density of the low-k film is known, constraints on the film thickness and the total aerial atomic density allow us extract the complete atomic composition of the low-k film from traditional backscattering spectrometry methods.

Citation

Journal of Applied Physics

Pub Type

Journals

Keywords

chemical composition, forward recoil spectrometry, forward scattering ion scattering, low-dielectric films rutherford backscat

Citation

Soles, C. , Composto, R. and Wang, H. (2008), The Chemical Composition of Low Dielectric Constant Films From Novel Ion Scattering Methodologies, Journal of Applied Physics (Accessed January 13, 2025)