Chemically Amplified Resist Composition for Immersion Lithography

The patent changes the chemical composition parameters of the resist film by incorporating fluorinated resin (b) with specific structural units (b1-b4) including acid-labile groups, hydroxyl groups, and lactone structures. This chemical parameter change increases the receding contact angle from conventional levels to 70-110°, thereby reducing fluid adhesion and preventing defect formation during post-exposure baking while maintaining reliable resist performance

The patent creates a composite resist system combining fluorinated resin (b) with non-fluorinated resin (a) containing acid-labile groups. The fluorinated resin (b) specifically contributes hydroxyl groups and lactone structures that increase receding contact angle, while the composite formulation balances fluid interaction properties to prevent droplet formation while maintaining pattern fidelity

The patent applies local quality by incorporating fluorine atoms at specific molecular locations within the resin structure rather than uniform distribution. The fluorinated resin (b) contains fluorine-substituted aromatic rings and aliphatic chains positioned to specifically interact with fluid surfaces, increasing receding contact angle without requiring complete fluorination of the entire resist system, thus managing complexity

The patent optimizes the concentration parameter of fluorinated resin (b) within the total resin content and controls the ratio between fluorinated resin (b) and non-fluorinated resin (a). By adjusting these compositional parameters, the patent achieves sufficient receding contact angle increase to suppress defects while avoiding excessive complexity in the resist formulation