AVS 49th International Symposium
    Surface Science Tuesday Sessions
       Session SS-TuP

Paper SS-TuP16
Interfactant-mediated Growth of Ultrathin Bismuth Films on Si(111)

Tuesday, November 5, 2002, 5:30 pm, Room Exhibit Hall B2

Session: Surface Science Poster Session
Presenter: J.T. Sadowski, Tohoku University, Japan
Authors: J.T. Sadowski, Tohoku University, Japan
T. Nagao, Tohoku University, Japan
Y. Fujikawa, Tohoku University, Japan
S. Kuwano, Tohoku University, Japan
T. Sakurai, Tohoku University, Japan
Correspondent: Click to Email
Semimetal bismuth (Bi) has quite distinctive electronic properties due to its covalent-like bonds, highly anisotropic Fermi surface and low carrier concentrations. The small carrier effective masses and the very long mean free path result in large MR effects observed in bulk single crystals of Bi. However, fabrication of high quality bismuth films with nanometer thickness, required for the technological applications, still appears to be difficult. Recently, we have found that ultrathin Bi layers deposited at room temperature on the Si(111)-7x7 surface exhibit 2D growth after forming initial rough transition layer, and self-organizes into a single crystal ultrathin film nearly perfectly aligned to the Si substrate. In this paper we report the scanning tunneling microscopy studies of the role of the interfactants of Au-induced surface superstructures in the growth of flat, very well ordered, ultrathin Bi films on Si(111) surface. The morphology of the Bi ultrathin film was found to be modified by the presence of interfactant surface superstructures since the growth kinetics is modified by the change in the diffusion length, nucleation density, and the interface free energy due to the modification in the atomic as well as domain-wall configuration. In the systematic study, the morphology and detailed atomic structure of the Bi layer grown on the various Au-induced surface superstructures such as 5x2, @alpha@-root3xroot3, and @beta@-root3xroot3-Au will be discussed and compared with the results of the direct Bi growth on the Si(111)-7x7 surface, as well as with growth on otherwise modified interfaces such as @alpha@-root3xroot3 and @beta@-root3xroot3-Bi superstructure.