Low-energy electron-microscopy investigations of orientational phase separation on vicinal Si(111) surfaces

Abstract

We have used low-energy electron microscopy to investigate in real time the thermodynamically driven faceting of stepped Si(111) surfaces into (7\ifmmode\times\else\texttimes\fi{}7) reconstructed (111) facets and ``step bunches.'' Our data are inconsistent with the thermodynamic expectation that an isolated linear facet should grow without limit: Instead we find that the width of the (7\ifmmode\times\else\texttimes\fi{}7) reconstructed (111) facets quickly reaches a constant maximum size. We discuss the possibility that elastic relaxations caused by the facet edges are responsible for the finite facet width.