Improving developability for application of iodine-containing materials to EUV lithography

Extreme Ultraviolet (EUV) lithography is essential for semiconductor miniaturization, necessitating enhanced resist performance for future nodes. Incorporating iodine into resists shows promise for improving EUV absorption, addressing issues like stochastic defects and low sensitivity. However, iodine's hydrophobicity can hinder development performance in water-based systems. This study examines the impact of nonionic surfactants on iodine-containing resists. We used ethylene oxide/propylene oxide block copolymers to mitigate hydrophobic interactions. Our findings reveal that certain surfactants improve lithographic properties, particularly resolution in Electron Beam (EB) patterning. This improvement is achieved by suppressing film swelling during development, as observed using the Quartz Crystal Microbalance (QCM) method. The significant improvement in development performance with certain surfactants suggests that poor dissolution arises from specific interactions inherent to the hydrophobic iodine group. Consequently, surfactant-containing developer solutions tailored to resist structures offer a promising approach for future miniaturization needs.