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Measurement of the Spatial Evolution of the Deprotection Reaction Front With Nanometer Resolution Using Neutron Reflectometry

Published

Author(s)

Eric K. Lin, Sushil K. Satija, Wen-Li Wu, Christopher L. Soles, D L. Goldfarb, B C. Trinque, S D. Burns, Ronald L. Jones, Joseph~undefined~undefined~undefined~undefined~undefined Lenhart, M Angelopoulos, C G. Willson

Abstract

The use of chemically amplified photoresists for the fabrication of sub-100 nm features will require spatial control with nanometer level resolution. To reach this goal, a detailed understanding of the complex reaction-diffusion mechanisms at these length scales is needed and will require high spatial resolution measurements. In particular, few experimental methods can directly measure the spatial evolution of the deprotection reaction front and correlate it with the developed structure. In this work, we demonstrate the complementary use of neutron (NR) and x-ray (XR) reflectometry to measure the reaction front profile with nanometer resolution.Using a bilayer geometry with a lower deuterium-substituted poly(tert-butoxycarboxystyrene) (d?PBOCSt) layer and an upper poly(hydroxystyrene) (PHOSt) layer loaded with a photoacid generator (PAG), we directly measure the spatial evolution of the reaction front. We show that the reaction front profile is broader than the initial interface after a post-exposure bake and the compositional profile changes upon development in an aqueous base solution. We also directly correlate the final developed structure with the reaction front profile. The spatial detail enabled by this general methodology can be used to differentiate between and evaluate quantitatively reaction-diffusion models.
Proceedings Title
Advances in Resist Processing and Technology, Conference | 19th | Advances in Resist Processing and Technology XIX | SPIE
Volume
4690
Issue
Pt. 1
Conference Dates
March 1, 2002
Conference Location
CA, CA
Conference Title
Proceedings of SPIE--the International Society for Optical Engineering

Keywords

nanofabrication, neutron reflectometry, photolithography, photoresist, polymer thin film, reaction front profile, x-ray reflector

Citation

Lin, E. , Satija, S. , Wu, W. , Soles, C. , Goldfarb, D. , Trinque, B. , Burns, S. , Jones, R. , Lenhart, J. , Angelopoulos, M. and Willson, C. (2002), Measurement of the Spatial Evolution of the Deprotection Reaction Front With Nanometer Resolution Using Neutron Reflectometry, Advances in Resist Processing and Technology, Conference | 19th | Advances in Resist Processing and Technology XIX | SPIE, CA, CA, [online], https://tsapps.nist.gov/publication/get_pdf.cfm?pub_id=852040 (Accessed February 29, 2024)
Created December 1, 2002, Updated February 17, 2017