ABSTRACT
Photoemission electron microscopy is used to study the growth of single-crystalline silver nanowires on flat and vicinal Si(001) substrates. The growth experiments were performed at various temperatures and showed a temperature dependence of nanowire formation. The nanowires on Si(001) are evenly distributed in the [110] and [Formula: see text] directions on the surface, whereas on a 4° vicinal surface the wires grow only along the steps, in the [Formula: see text] direction. This change in wire distribution is attributed to the increasing diffusion anisotropy as the vicinality of the substrate increases.
ABSTRACT
Photoemission electron microscopy is used to study the thermal decay of Ag islands grown epitaxially on Si(001) surfaces. (2 x 3) Ag reconstructed zones, due to migrating Ag atoms supplied to the surface by the decaying islands, surround each of the islands. The shape of these reconstructed zones depends on the degree of diffusion isotropy in the system. We demonstrate that the imaging of these reconstructed "isocoverage zones" constitutes a unique experimental method for directly observing diffusion fields in epitaxial systems. We describe the dynamics of the thermal decay of the islands and the isozones in the context of a continuum diffusion model.
