Chlorine-induced restructuring processes on Cu/Si(111) “5×5” surfaces were studied with Auger electron spectroscopy and scanning tunneling microscopy techniques. The copper Auger signal intensities from these surfaces (each with different chlorine exposures and subsequent 450 °C annealing), decreased with increasing initial chlorine exposures. At a Cl-coverage equal to ∼1 ML (after annealing) the Cu signal decreased below the detection limit. The associated restructuring processes were also explored. Initially homogeneous Cu/Si(111) “5×5” surfaces, with Cl-exposures and annealing, separate into coexisting areas of Cu-free Cl/Si(111) 1×1 and nearly chlorine-free areas of Cu/Si(111) “5×5.” The original copper density is conserved by formation of three-dimensional Cu3Si crystallites on the surface. The restructuring is completely reversible; upon desorption of all chlorine at ∼600 °C the surface resumes its original Cu/Si(111) “5×5” structure. Possible implications for the atomic scale mechanisms in the direct synthesis of methylchlorosilanes from Cu/Si surfaces are discussed.
|Original language||English (US)|
|Journal||Physical Review B - Condensed Matter and Materials Physics|
|State||Published - 2003|
All Science Journal Classification (ASJC) codes
- Electronic, Optical and Magnetic Materials
- Condensed Matter Physics