Hydroxyphenylbenzene derivatives as glass forming molecules for high resolution photoresists

This paper presents a fundamental study to relate molecular architecture to the amorphous properties of hydroxyphenylbenzene molecular glass derivatives. These studies demonstrates that the branched hydroxyphenylbenzene derivatives can form stable molecular glasses despite the π–π interactions present. Through this research, design concepts to stabilize the amorphous nature and to increase the glass transition temperature (Tg) based on asymmetric molecular structures, bulky substituents, conformation states and molecular size are explored. An understanding of such behavior is important for the development of hydroxyphenylbenzene derivatives as potential molecular photoresists for patterning below 50 nm. This research has helped to identify potential candidates to be evaluated as positive-tone photoresists for lithographic applications for extreme ultraviolet (EUV, λ = 13.4 nm) lithography. The first reported sub-30 nm feature sizes for hydroxyphenylbenzene derivatives were demonstrated with high Tg materials.