Articolo in rivista, 2022, ENG, 10.1016/j.apsusc.2022.155763

Effects of an epitaxial graphene layer for the growth of nickel silicides on a Ni(111) substrate

Fabio Ronci, Stefano Colonna, Roberto Flammini, Maurizio De Crescenzi, Manuela Scarselli, Matteo Salvato, Isabelle Berbezier, Holger Vach, Paola Castrucci

Istituto di Struttura della Materia, CNR (ISM-CNR), 00133 Roma, Italy Dipartimento di Fisica, Università degli Studi di Roma "Tor Vergata", 00133 Roma, Italy CNRS, Aix-Marseille Universitè, IM2NP, UMR 7334, Campus de St. Jerome, 13397 Marseille, France LPICM, CNRS, Ecole Polytechnique, IP Paris, 91128 Palaiseau, France

In this paper, we report on an in-depth study on the growth of nickel silicides, either on a clean Ni(111) substrate or in the presence of a previously-grown epitaxial single graphene (Gr) layer, by means of Auger electron spectroscopy (AES), low energy electron diffraction (LEED), and scanning tunneling microscopy (STM). We demonstrate that two different nickel silicides, namely Ni3Si and Ni2Si, progressively form as the annealing temperature is increased from 450 °C to 600 °C. The presence of the Gr layer does not change the nature of the two silicide phases but rather affects the morphology of the silicide overlayer. Indeed, in the presence of Gr, the deposited silicon atoms intercalate by passing through the Gr defects or domain boundaries and accumulate on specific sample areas, resulting in the formation of multilayer silicide islands. In the absence of Gr, the deposited silicon atoms react uniformly with the nickel substrate, resulting in the formation of homogeneous large scale silicide layers.

Applied surface science 611 , pp. 155763–?

Keywords

Graphene, Nickel, Nickel silicide, Auger electron spectroscopy, Low energy electron diffraction, Scanning tunneling microscopy

CNR authors

Colonna Stefano, Ronci Fabio, Flammini Roberto

CNR institutes

ISM – Istituto di struttura della materia