Polymerizable Nonionic Perfluorinated Photoacid Generators for High-Resolution Lithography.

Area of Science:

• Materials Science
• Chemistry
• Nanotechnology

Background:

• Chemically amplified photoresists face challenges with acid diffusion, limiting resolution, line-edge roughness, and sensitivity.
• Achieving high-resolution lithography requires overcoming the trade-off between these critical parameters.

Purpose of the Study:

• To develop novel photoacid generators (PAGs) that enhance sensitivity and minimize acid diffusion for advanced lithography.
• To synthesize PAG-bound polymers for improved resolution in nano-patterning.

Main Methods:

• Development of alkene-functionalized nonionic perfluorinated photoacid generators (PAGs).
• Synthesis of polymerizable PAG monomers and PAG-bound polymers.
• Evaluation of lithography performance, including sub-45 nm line patterning.

Main Results:

• Fluorine-rich PAGs exhibit enhanced photochemical reactivity, improving photoresist sensitivity.
• Generated sulfonic acids have large sizes and minimal diffusion, effectively suppressing acid diffusion.
• Sub-45 nm lines were patterned at an electron beam dose of 29 µC cm⁻² using PAG-bound polymer photoresists.

Conclusions:

• The developed perfluorinated PAGs offer a promising solution for high-sensitivity and high-resolution nano-patterning.
• PAG-bound polymers further enhance resolution by minimizing acid diffusion.
• These materials are suitable for advanced lithography applications requiring stringent performance metrics.