AVS 64th International Symposium & Exhibition
    Thin Films Division Tuesday Sessions
       Session TF-TuA

Paper TF-TuA2
Surface Chemistry of Ru Atomic Layer Deposition Precursors

Tuesday, October 31, 2017, 2:40 pm, Room 20

Session: ALD Precursors and Surface Reactions
Presenter: Francisco Zaera, University of California
Authors: X. Qin, University of California
F. Zaera, University of California
Correspondent: Click to Email
The thermal chemistry on nickel, silicon oxide, and aluminum oxide surfaces of tris(2,2,6,6-tetramethyl-3,5-heptanedionato)ruthenium(III), a precursor used for the growth of metallic ruthenium thin films via atomic layer deposition (ALD), was characterized by using a combination of X-ray photoelectron spectroscopy (XPS), temperature programmed desorption (TPD), and reflection-absorption infrared absorption spectroscopy (RAIRS). Several intermediate steps were identified during the surface decomposition of this precursor on nickel, with the release of carbon monoxide into the gas phase, the formation of tert-butyl species on the nickel substrate, and the reduction of the metal center in stepwise fashion between approximately 300 and 500 K. ALD cycles with oxygen as the second reagent accomplish the efficient removal of all carbon contaminants from the surface and the reversible oxidation-reduction of the metal, indicating the feasibility of growing metallic films with such oxidizing reactant. However, the formation of volatile Ru oxides prevents the buildup of multilayers of the metal. Experiments with other oxidants (nitrous oxide) and other substrates show promise for finding a solution to this problem.