Synthesis, Pore Morphology, and Dielectric Property of Mesoporous Low-k Material PSMSQ using a Reactive High-Temperature Porogen, TEPSS

Abstract

A high-temperature reactive porogen, triethoxy(polystyrene) silane (TEPSS) (M-w=3,500 g/mole), suitable for late-porogen removal integration scheme has been synthesized in p-xylene via atom transfer radical polymerization. TEPSS was then grafted onto poly(methyl-silsesquioxane) (MSQ) matrix (k=2.9) to circumvent possible phase separation between matrix and porogen in the hybrid approach and porogen aggregation. Our results shows porous low-k MSQ films possess uniform pore size, 24 nm for porosity up to 40%, primarily due to low PDI and reactive porogen, and the dielectric constant is decreased to 2.37 at 40% porosity. In addition, less porogen aggregation was observed at porogen loading similar to 40 v%.