Thin Film Confinement Effects on the Thermal Properties of Model Photoresist Polymers

Published

December 1, 2001

Author(s)

Christopher L. Soles, Eric K. Lin, Joseph~undefined~undefined~undefined~undefined~undefined Lenhart, Ronald L. Jones, Wen-Li Wu, D L. Goldfarb, M Angelopoulos

Abstract

The demand to print increasingly smaller microelectronic device features means that the thickness of the polymer films used in the lithographic processes must decrease. The thickness of these films is rapidly approaching the unperturbed dimensions of the polymer, length scales at which confinement deviations and dewetting are a significant concern. We combine specular X-ray reflectivity (SXR) and incoherent neutron scattering (INS) to probe the thermal stability and dynamical effects of thin film confinement in poly(hydroxy styrene) (PHS), a polymer used in a majority of the 248 nm deep UV photoresists. PHS forms stable thin films (down to 5 nm) that do not dewet over a wide temperature range on Si surfaces ranging from hydrophilic to hydrophobic. The surface energy has a profound influence on the magnitude of the thin film expansion coefficient, especially above the glass transition, in films as thick as 100 nm. Confinement also appears to suppress the mean-square atomic displacements and the level of anharmonicity in the dynamics, primarily above the bulk glass transition.

Citation

Journal of Vacuum Science and Technology B

Volume

19

Issue

No. 6

Pub Type

Journals

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Keywords

confinement, glass transition, incoherent neutron scattering, photolithography, thin films, x-ray reflectivity

Citation

Soles, C. , Lin, E. , Lenhart, J. , Jones, R. , Wu, W. , Goldfarb, D. and Angelopoulos, M. (2001), Thin Film Confinement Effects on the Thermal Properties of Model Photoresist Polymers, Journal of Vacuum Science and Technology B, [online], https://tsapps.nist.gov/publication/get_pdf.cfm?pub_id=851889 (Accessed April 25, 2024)