Enhanced Acid Diffusion Control by Using Photoacid Generator Bound Polymer Resist.

Area of Science:

• Polymer Chemistry
• Materials Science
• Lithography

Background:

• Photoacid generators (PAGs) are crucial for photoresist performance, but acid diffusion affects resolution and line edge roughness (LER).
• PAG aggregation and uncontrolled acid diffusion are significant challenges in conventional photoresist formulations.

Purpose of the Study:

• To synthesize and characterize a novel PAG-bound polymer resist.
• To evaluate the lithographic performance of the PAG-bound resist compared to a PAG-blended system.
• To demonstrate the benefits of covalently incorporating PAGs into the polymer matrix for improved photoresist characteristics.

Main Methods:

• Synthesis of a triphenyl sulfonium salt methacrylate as a PAG.
• Copolymerization of the PAG with glycidyl methacrylate and methyl methacrylate via radical reaction.
• Characterization using 1H NMR and evaluation of lithographic performance using ArF lithography.

Main Results:

• Successful synthesis and characterization of the PAG-bound polymer resist.
• The PAG-bound resist demonstrated superior performance in ArF lithography.
• Significant improvements in line edge roughness (LER) and higher resolution were observed compared to PAG-blended resists.

Conclusions:

• Covalent incorporation of PAGs into polymer resists effectively controls acid diffusion and mitigates PAG aggregation.
• The developed PAG-bound polymer resist offers enhanced resolution and reduced LER, outperforming traditional PAG-blended systems.
• This approach represents a significant advancement in photoresist technology for high-performance lithography.