Investigation of boron-doped silicon(111) surface structure and metal silicide interface formation

Surface atomic structure, adsorbate atom sites and interface formation of epitaxial metal disilicides on boron doped Si(111) substrates are investigated using Rutherford backscattering, ion channeling, low energy electron diffraction, and Auger electron spectroscopy techniques along with Monte Carlo simulations and Hartree Fock cluster calculations.; Transmission ion channeling was used to study the effect of B concentration on the lattice site of chemisorbed Br on Si(111) thin crystals. For B concentrations less than {dollar}sim{dollar}7 {dollar}times{dollar} 10{dollar}sp{lcub}19{rcub}{dollar} cm{dollar}sp{lcub}-3{rcub}{dollar} in the substrate, the observed Br adsorption site is confirmed to be the expected a-top position. This Br adsorption site is found to be perturbed at a higher B concentration ({dollar}sim{dollar}2 {dollar}times{dollar} 10{dollar}sp{lcub}20{rcub}{dollar} cm{dollar}sp{lcub}-3{rcub}{dollar}).; The investigation of atomically clean surfaces of highly B-doped Si(111) is reported. Accumulation of B at the Si surface after in-situ annealing is found to lead to the formation of a ({dollar}surd{dollar}3 x {dollar}surd{dollar}3)R30{dollar}spcirc{dollar} reconstruction. Theoretical cluster calculations for B and Al adsorption sites show that the location for B atoms (B{dollar}sb5{dollar} site) is different from that reported for other group III elements (T{dollar}sb4{dollar} site). Measured and calculated atomic arrangements for this surface structure are also presented.; An extensive in-situ study of room temperature interface formation of metal silicides on Si(111){dollar}surd{dollar}3 x {dollar}surd{dollar}3 surfaces suggests that the first monolayer of metal atoms (Co or Ni) diffuses to reaction sites in a subsurface layer of the Si(111) substrates where metal silicide growth begins. Further metal deposition (up to {dollar}sim{dollar}3 ML) leads to the growth of a metal disilicide film which acts as a diffusion barrier that terminates further formation of metal disilicide at room temperature.