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In the paper the ability of TOF–LEIS to analyse the thickness and growth modes of Ga and Ga-N ultra thin films was demonstrated. It is shown that multiple scattering, which usually complicates the spectra evaluation, can be successfully used for the thickness determination of ultra thin films. A linear dependence of the half-width of the Ga peak on the Ga-surface coverage within the range of 1–9 ML in the TOF–LEIS spectrum of Ga layers grown on Si(1 1 1) was found. Additionally, the development of Ga- and Si-peak heights with the Ga-surface coverage suggests the Ga layers grow in the way close to the layer-plus-island growth mode. [Copyright &y& Elsevier]

Abstract: The influence of atomic hydrogen on the Si(100) substrate with submonolayer gallium surface phases – (2×3), (2×2) and (8×1) – as well as the deposition of gallium on monohydride terminated Si(100)–(2×1)-H surface were studied by synchrotron radiation photoelectron spectroscopy (SR-PES) and low energy electron diffraction (LEED) and compared with similar metal/Si systems. It was found that gallium deposition on the Si(100)–(2×1)-H surface at elevated temperature (400°C) leads to a complete hydrogen desorption and formation of the same gallium surface phases as on the bare Si(100)–(2×1). Exposing the Si(100) substrate with (2×3)-Ga and (2×2)-Ga surface phases to atomic hydrogen results in the formation of gallium nanoclusters, surrounded by the Si(100)–(2×1)-H surface. These clusters have more than 2 monolayers in height and cover approximately 20–26% of surface, depending on the initial coverage. The results indicate that the cluster size and density may be controlled by initial Ga coverage and possibly by temperature. [Copyright &y& Elsevier]