UHV Surface Chemistry of bis(ethylcyclopentadienyl)ruthenium, (C₂H₅C₅H₄)₂Ru on an Oxide Substrate

Abstract

The interactions of an organometallic precursor to Ru thin films, bis(ethylcyclopentadienyl)ruthenium, (C 2 H 5 C 5 H 4 ) 2 Ru, with an amorphous Al 2 O 3 substrate were probed using tools of ultra-high vacuum surface science. The precursor adsorbs and desorbs with no decomposition on Al 2 O 3 that is bare, or covered with patches of O-saturated Ru. In the absence of pre-existing Ru sites, there was no reaction up to 950 K with or without co-dosed O 2 at pressures up to 10 ±6 torr. Film-forming reactions do occur under UHV dosing conditions when Ru sites and chemisorbed oxygen are both present. The distribution of chemical states of surface oxygen changes with temperature and influences reaction kinetics and film growth.

Surface chemistry of (2,4-dimethylpentadienyl)(ethylcyclopentadienyl)Ru on polycrystalline Ta

“…Extrapolating the desorption energy back to the limit of zero coverage gives a multilayer desorption energy of 0.9 eV (87 kJ/mol). This value is in good agreement with the desorption energy for the organometallic precursor Ru(EtCp) 2 , which forms clusters on an Al 2 O 3 substrate held at 110 K and exhibits a desorption energy of 94 kJ/mol [38].…”

Deposition of Palladium from a Cylcopentadienyl‐allyl‐palladium Precursor on Si‐Based Substrates with Various Pretreatments: The Role of Surface Si–OH and Si‐H Species Studied by X‐Ray Photoelectron Spectroscopy

“…The observation that the metal deposition from a CVD precursor onto a surface is only effective if the surface is able to provide free atoms for the precursor decomposition reaction has also been observed for a different system (a ruthenium precursor on an aluminum oxide substrate). [33] Ru deposition is only observed if free oxygen species are made available on the surface whereas a bare stoichiometric aluminum oxide surface is rather inactive for Ru deposition.…”

Structure and morphology of Ru films grown by atomic layer deposition from 1-ethyl-1’-methyl-ruthenocene

“…In some earlier ALD studies, Al 2 O 3 has been used as the layer conveniently promoting the nucleation of ruthenium [20,21,43]. The nucleation of Ru on other amorphous substrates (soda lime glass and/or SiO 2 ) has been relatively poor, virtually not enabling the growth of Ru from certain precursors such as RuCp 2 or Ru(thd) 3 without nucleation layers.…”

“…When passing from bulk to surface sensitivity, the intensity of the oxide component increased relative to the metal. This means that the oxide is present only at the surface either as a residue of the oxidative decomposition process with subsurface oxygen [43] or as a result of the exposure of the Ru surface to environmental air. The sample was further cleaned by sputtering with Ar + ions.…”