Precursor design and cascade mechanism of RuO2·xH2O atomic layer deposition.

[Display omitted] • Reactions of bis(cyclopentadienyl) ruthenium (ruthenocene, RuCp 2) and cyclopentadienyl pyrrolyl ruthenium (RuCpPy) on the hydroxylated surface were explored by density functional theory calculations. • Ru precursors, such as bis(pyrrolyl) ruthenium (RuPy 2), were designed for H 2 O-based atomic layer deposition of RuO 2 · x H 2 O. • New cascade mechanism of H 2 O-based atomic layer deposition of RuO 2 · x H 2 O was proposed. As the unique nanofabrication technique, atomic layer deposition (ALD) can be used to deposit high-quality, uniform, and conformal nanoparticle coatings. Ru and its oxides (RuO x) are important materials in the fields of microelectronics and catalysis. In this work, the reaction of Ru precursors with different ligands on the hydroxylated surfaces were explored. The elimination of the pyrrolyl (Py) ligand is easier than that of the cyclopentadienyl (Py) ligand on the hydroxylated surface. The reaction involved in RuO 2 · x H 2 O ALD using RuPy 2 and H 2 O as precursors was further investigated. During the RuPy 2 reaction, the pyrrolyl ligand is eliminated by the substitution reaction with a surface hydroxyl group. However, the desorption of the pyrrole molecule is difficult due to the strong adsorption between the pyrrole molecule and Ru surface. During the H 2 O reaction, the H 2 O molecules further help the elimination of pyrrolyl ligands from the surface and the dissociative desorption of pyrrole molecules This unique reaction mechanism involved in the ALD of RuO 2 with the assistance of H 2 O can be termed new cascade mechanism. These findings provide theoretical guidance for precursor design and ALD growth of metal oxides. [ABSTRACT FROM AUTHOR]