Molecular Functionality Switching of Isomorphic Organoantimony Complexes between High-Sensitivity Radical Initiator and Quencher for Reliable Extreme Ultraviolet Lithography

Abstract

Organoantimony photoresists, such as triphenyl antimony diacrylate, offer high extreme ultraviolet (EUV) sensitivity but are limited in thermal stability and uncontrolled polymerization. Herein, facile control of the photochemical properties and thermal stability of tris(methylphenyl) antimony diacrylate complexes with ortho-, meta-, and para-substituted methyl groups is demonstrated. Para-substituted complexes (p-Sb) exhibit high EUV sensitivity (11 mJ/cm2) but suffer from poor thermal stability. In contrast, ortho-substituted complexes (o-Sb) sterically hinder radical propagation by blocking access to the unsaturated core, thereby functioning as polymerization quenchers with reduced EUV sensitivity (220 mJ/cm2) and enhanced thermal stability. The positional modulation of isomorphic molecules enables the facile switching of photochemical functionality-serving as either a photoresist or quencher. A molecular glass resist formed by blending p-Sb with o-Sb achieves a high EUV sensitivity of 25 mJ/cm2 and thermal robustness up to 110 degrees C, producing scum-free CD 198 nm 1:1 line and space patterns with ArF lithography and CD 32 nm patterns at 38 mJ/cm2 with EUV.