A negative tone photoresist film, consisting of a molecular glass, a photoacid generator, and an acid labile crosslinker, was prepared by physical vapor deposition, a solvent‐free process. Subsequent to deposition, the coevaporated monomers were exposed using 365 nm radiation, subjected to a post exposure bake step, and developed in aqueous base to produce sub‐micron patterns. Combinatorial techniques were used to aid optimization of the photoresist by systematic variations in composition and exposure dose. Development factors such as concentration and time were also optimized.

Photoresists based on molecular glasses are gaining more and more importance as resist material to replace polymer based photoresist. In addition environmental issues have to be considered in the long-term. Therefore the paper describes novel negative photoresists containing a ternary mixture of a glassy low molecular functional polyphenol where the film preparation is possible by solvent-free physical vapor deposition. After UV light exposure and a thermal annealing process to enable acid catalyzed crosslinking between the molecular glass and the crosslinker, the photoresist was developed using only water to give well-defined patterns. In order to experimentally study efficiently the multiple parameters such as composition, exposure dose, and development times combinatorial PVD techniques were utilized.

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