Diffusion, nucleation and annealing of Co on the H-passivated Si(100) surface

• Published in: Surface science 1998-09, Vol.412, p.509-517
• Main Authors: Palasantzas, G., Ilge, B., de Nijs, J., Geerligs, L.J.
• Format: Article
• Language: English
• Subjects: Applied sciences; Cross-disciplinary physics: materials science; rheology; Exact sciences and technology; Growth; Materials science; Metals. Metallurgy; Methods of deposition of films and coatings; film growth and epitaxy; Nucleation; Physics; Scanning tunneling microscopy; Surface relaxation and reconstruction; Vacuum deposition
• ISSN: 0039-6028; 1879-2758
• DOI: 10.1016/S0039-6028(98)00481-6

We investigate the diffusion, nucleation and annealing behaviour of Co on H-passivated Si(100) surfaces by scanning tunneling microscopy (STM). Due to the absence of nucleation sites for silicide formation, the nucleation and growth mode is dominated by the formation of non-epitaxial islands which merge by increasing Co coverage θ. The island number density N shows a power law dependence on coverage N∝ θ c ( c=0.29±0.03) for room temperature deposition. Annealing at temperatures up to ∼400°C results in small changes of the Co clusters, while deposition at elevated substrate temperatures (∼400°C) results in the formation of fewer but coarser Co islands. Finally, at higher annealing temperatures (∼490°C) where H desorption takes place, the formation of two-dimensional islands occurs which are surrounded by an irregular 2× n ( n>1) reconstructed surface due to interstitial diffusion of Co into Si.