Platinum atomic layer deposition on metal substrates: A surface chemistry study

•MeCpPtMe3 adsorption on Ni is self-limiting up to 625 K, grows multilayers at higher Ts.•O2 treatment removes all carbon from the surface and grows a thin nickel oxide film on top.•Further MeCpPtMe3 dosing reduces that NiO back to metallic nickel.•Pt migrates to the layer below the NiO film and mixes with the Ni(0) substrate.•Because of that, no Pt films grow on top of Ni by this ALD process. The surface chemistry associated with the atomic layer deposition (ALD) of platinum films on metallic nickel substrates using trimethyl(methylcyclopentadienyl)platinum(IV) (MeCpPtMe3) and oxygen was characterized by using X-ray photoelectron spectroscopy (XPS). The uptake of the MeCpPtMe3 ALD precursor was found to be self-limiting between 525 and 625 K, but to lead to multilayer deposition at 675 K. The adsorbed species display a C:Pt ratio of approximately 5:1, suggesting that all methyl moieties are lost upon activated bonding to the surface but that the methylcyclopentadienyl group remains coordinated to the adsorbed Pt atoms. Oxygen treatment of that surface leads to the complete removal of the carbon-containing species from the surface and to the formation of a thin NiO film. Further dosing with MeCpPtMe3, in the next ALD cycle, fully reduces that NiO film to metallic Ni(0) and adds more Pt to the surface. However, no Pt film buildup was seen after several ALD cycles. Angle-resolved XPS data suggested that the deposited Pt migrates below the NiO that forms during the O2 exposures and possibly alloys with the metallic Ni substrate at that stage. [Display omitted]