Process for increasing the etch resistance and for reducing the hole and trench width of a photoresist structure using solvent systems of low polarity

A process for chemically amplifying structured resists, which comprises:

• applying a chemically amplified photoresist to a substrate, the photoresist having a film-forming polymer including acid-labile groups for being cleaved under action of an acid and liberating polar groups resulting in an increase in a solubility of the film-forming polymer in aqueous alkaline developers, the film-forming polymer also including anchor groups for linking amplification agents, the photoresist also including a photo acid generator and a first solvent in which the film-forming polymer is soluble;
• drying the photoresist to obtain a resist film;
• exposing the resist film, section-by-section, such that an exposed resist is obtained and such that the photo acid generator liberates an acid in exposed parts of the resist film;
• heating the exposed resist to cleave the acid-labile groups in the exposed parts of the resist and to liberate the polar groups on the film-forming polymer such that nonpolar resist sections and polar resist sections are obtained;
• developing the resist with an aqueous alkaline developer to detach the polar resist sections from the substrate and to obtain a structured resist, the aqueous alkaline developer having a higher polarity than the first solvent, and the film-forming polymer being insoluble in the aqueous alkaline developer;
• applying an amplification agent to the structured resist, the amplification agent being dissolved in a second solvent having a lower polarity than the first solvent, the film-forming polymer being substantially insoluble in the second solvent, and the amplification agent having at least one reactive group for reacting with at least one of the anchor groups of the film-forming polymer to link the amplification agent to the film-forming polymer;
• and
• removing excess amplification agent using a third solvent having a lower polarity than the first solvent, the film-forming polymer being insoluble in the third solvent.