The Deprotection Reaction Front Profile for Model 193 nm Methacrylate-Based Chemically Amplified Photoresists

Published

March 1, 2006

Author(s)

B D. Vogt, Shuhui Kang, Vivek Prabhu, Ashwin Rao, Eric K. Lin, Sushil K. Satija, Karen Turnquest, Wen-Li Wu

Abstract

An understanding of acid diffusion-reaction in chemically amplified photoresists during the post-exposure bake (PEB) is critical for both critical dimension (CD) and line edge roughness (LER) control. Despite its importance, there remains a lack of fundamental understanding of the diffusion-reaction process. This is due in part to the complex interplay between diffusion and reaction where the deprotection of the resin modifies the local acid diffusivity which in turn changes the rate of deprotection. Here, we report the direct measurement of the reaction diffusion front at a model line edge from neutron reflectivity and Fourier transform infrared spectroscopy.Variation in the photoacid generator size influences the reaction extent and breath of the deprotection profile. A larger photoacid results in a sharper deprotection profile and a shorter reaction length. Under the same post-exposure bake time and temperature the smaller photoacid leads to a much broader deprotection profile. These measurements illustrate the complexity of the reaction-diffusion process.

Proceedings Title

Proceedings of SPIE

Volume

483

Conference Dates

February 19-24, 2006

Conference Location

San Jose, CA, US

Conference Title

SPIE Advanced Lithography

Pub Type

Conferences

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Keywords

chemically amplified photoresists, diffusion, neutron reflectivity, photolithography

Citation

Vogt, B. , Kang, S. , Prabhu, V. , Rao, A. , Lin, E. , Satija, S. , Turnquest, K. and Wu, W. (2006), The Deprotection Reaction Front Profile for Model 193 nm Methacrylate-Based Chemically Amplified Photoresists, Proceedings of SPIE, San Jose, CA, US, [online], https://tsapps.nist.gov/publication/get_pdf.cfm?pub_id=852589 (Accessed October 8, 2025)