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O: Fachverband Oberflächenphysik
O 63: Oxides and Insulator Surfaces: Adsorption and Reaction of Small Molecules II
O 63.6: Talk
Wednesday, March 19, 2025, 11:45–12:00, H25
Nucleation of TMDAH on CoO nanoislands on Au(111) — •Jonas Hauner, Nikolai Sidorenko, Hanna Bühlmeyer, and Jörg Libuda — Interface Research and Catalysis, Friedrich-Alexander-Universität Erlangen-Nürnberg, Egerlandstraße 3, 91058 Erlangen, Germany
Atomic layer deposition (ALD) has recently received considerable attention as a promising method to precisely grow thin films of a wide variety of materials. This work focuses on the ALD of HfS2 on oxide substrates. In specific, we report on the nucleation behavior of the ALD precursor tetrakis(dimethylamido)hafnium(IV) (TMDAH) on cobaltoxide nanoislands on Au(111). The samples were prepared by deposition of Co in oxygen atmosphere and subsequent deposition of TMDAH. We investigated the adsorption of TMDAH by scanning tunneling microscopy (STM) and infrared absorption reflection spectroscopy (IRAS). At 300 K, TMDAH nucleates at OH groups at the CoO surface by means of a Brønsted acid-base reaction. At 400 K, the mechanism changes and involves a Lewis acid-base reaction due to the lack of OH groups on the substrate. Presaturation of the substrate with H2O further modifies the reaction mechanism of nucleation.
Keywords: Atomic Layer Deposition; Cobalt Oxide; Infrared Reflection Absorption Spectroscopy; Scanning Tunneling Microscopy