Diverse growth of Mn, In and Sn islands on thallium-passivated Si(111) surface

• Published in: Applied surface science 2015-03, Vol.331, p.339-345
• Main Authors: Matvija, P., Sobotík, P., Ošťádal, I., Kocán, P.
• Format: Article
• Language: English
• Subjects: Adsorbates; Deposition; Diffusion; Diffusion welding; Growth modes; Islands; Manganese; Passivation; Reaction kinetics; Scanning tunneling microscopy; Thallium; Thin film growth; Tin
• ISSN: 0169-4332; 1873-5584
• DOI: 10.1016/j.apsusc.2015.01.067

[Display omitted] •Tl-(1×1) layer highly enhances diffusion of adsorbates on the Si(111) surface.•Growth of ad-layers on the Si(111)/Tl surface resembles the growth on metal surfaces.•Dendritic growth in the case of Mn on Si(111)/Tl.•Compact and unstable 2D islands in the case of In on Si(111)/Tl.•Triangular islands of intermixed Sn and Tl in the case of Sn on Si(111)/Tl. Controlled growth of thin films on highly reactive silicon surfaces has been a challenge for decades. High density of surface dangling bonds, however, hinders the adsorbate diffusion and its self-organization. In our work, we propose a novel use of the Tl-(1×1) layer as a passivating agent, which highly enhances diffusion of adsorbates by saturating all dangling bonds of the Si substrate. We use room-temperature scanning tunneling microscopy to study structures formed on the Si(111)/Tl−(1×1) surface after deposition of submonolayer amounts of three elemental adsorbates: Mn, In and Sn. As a result, three significantly different surface structures are observed. Manganese atoms aggregate to stable dendritic islands nucleated on Si steps. Indium islands are compact and unstable during observation. Unlike Mn and In, Sn atoms intermix with Tl atoms and arrange into an array of triangular objects. The growth kinetics of the three deposited metals on the Tl−(1×1) layer is discussed and compared with the kinetics observed in previously studied systems. The comparison shows that the growth of the layers adsorbed on the Tl-passivated surface is similar to the growth of the adsorbate layers on less reactive metal surfaces.