Resist Composition Hydrophobicity via Fluorine Additive

The patent changes the chemical composition parameters of the resist film by incorporating fluorinated compounds (compounds containing CF3 groups or perfluoroalkyl groups) to modify the surface properties. This parameter change increases the contact angle with water from conventional values to 40° or more, thereby reducing substance elution into the liquid immersion solvent and preventing deterioration of lithography characteristics

The patent creates a composite resist composition by combining base resin components with specific fluorinated compounds (compounds of formula (1) where R1-R6 are specific hydrocarbon or fluorinated groups). This composite material approach integrates hydrophobic fluorinated segments into the resist matrix, providing both the necessary lithographic performance and resistance to water-based solvent elution

The patent defines specific compositional parameters for the fluorinated compounds (formula (1) with specific R1-R6 groups and n values of 1-4) and their content in the resist composition (0.1-10 wt%). By controlling these parameters, the patent achieves the desired hydrophobicity (contact angle ≥40°) while maintaining composition manageability and avoiding excessive complexity

The patent introduces fluorinated compounds with specific local molecular structures (CF3 groups, perfluoroalkyl groups) at strategic positions within the resist composition. These localized fluorinated segments provide hydrophobicity at the film-solvent interface without requiring complete restructuring of the entire resist composition, thus balancing performance improvement with compositional simplicity