Growth and reconstructions of Pb ultrathin films on Si(100) surfaces

The initial stages of room temperature growth of Pb overlayers on commercial Si(100) p ( 2 × 1 ) surface have been investigated using low-energy electron diffraction and low-energy electron microscopy (LEEM) techniques. A well-ordered reconstructed Si(100) p ( 10 × 2 ) surface phase has been observed for 0.5 monolayers of Pb deposition and is found to vanish for higher Pb coverages. We do not observe any island formation in our LEEM studies during the early stages of growth, unlike earlier studies on low-miscut substrates. Our dark-field LEEM experiments suggest the observed high step density with low terrace widths is responsible for this behaviour.