Search

Abstract: A surface preparation method with fine SiO2 particles in water is developed to flatten Si(001) surfaces on the nanometer scale. The flattening performance of Si(001) surfaces after the surface preparation method is investigated by scanning tunneling microscopy. The observed surface is so flat that 95% of the view area (100×100nm2) is composed of only three atomic layers, namely, one dominant layer occupying 50% of the entire area and two adjacent layers. Furthermore, a magnified image shows the outermost Si atoms regularly distributed along the 〈110〉 direction on terraces. [Copyright &y& Elsevier]

We have studied the dissociative adsorption process of halogen molecules (Cl2 and F2) on the Si(0 0 1) surface by first-principles molecular-dynamics (FPMD) calculations and scanning tunneling microscopy (STM) observations. From FPMD calculations, we demonstrate that Cl2 and F2 molecules adsorb dissociatively at dangling bonds of a buckled dimer with no energy barrier, so that the buckled dimer becomes geometrically flat. In addition, STM observations show that the dissociative adsorptions of Cl2 and F2 induce buckled dimers at the SA step on the Si(0 0 1)-(2×1) surface to become symmetric dimers, in good agreement with the results of FPMD calculations. [Copyright &y& Elsevier]