Halogens on Si(100): complexities of a simple system

C.M. ALDAO

Sao Pedro, SP

Simposio; The Fifth San Luis Symposium on Surfaces, Interfaces and Catalysis: PASI/San Luis Summer School; 2010

Despite the large number of phenomena that can take place at surfaces, we hope that there is a small number of basic laws governing the occurring processes and the resulting final morphologies. However, it is found that surface processes can be remarkably complex, even for simple systems. Si(100) etching with halogens seems to be a simple model system at first sight, with a single reaction product. Surprinsingly, a variety of phenomena are present that directly affect etching and surface morphology. We will show that adsorbates destabilize Si(100), that vacancies are needed for roughening, that roughening patterns depend on halogen-halogen and halogen-substrate interactions, that there is more than a single reaction pathway, that internal electrons activate desorption to create halogen-free dimers, and that dangling bonds allow uptake beyond saturation.