AVS 46th International Symposium
    Surface Science Division Wednesday Sessions
       Session SS1-WeM

Paper SS1-WeM9
A Novel STM Imaging Mechanism Used to Resolve the Atomic Structure of the As-Rich GaAs(001)-(2x4) Surface

Wednesday, October 27, 1999, 11:00 am, Room 606

Session: Surface Structure
Presenter: V.P. LaBella, University of Arkansas
Authors: V.P. LaBella, University of Arkansas
D.W. Bullock, University of Arkansas
P.M. Thibado, University of Arkansas
P. Kratzer, Max-Planck-Gesellschaft, Germany
M. Scheffler, Max-Planck-Gesellschaft, Germany
Correspondent: Click to Email
Motivated by the importance of GaAs in the compound semiconductor device market. The atomic arrangement of the technologically important GaAs(001)-(2x4) reconstructed surface is determined using scanning tunneling microscopy (STM) and first-principles, electronic structure calculations. The bias-dependent STM images reveal the relative position and depth of atomic-scale features within the trenches between the top layer As dimers, which are in agreement with the @beta@2 (2x4) structural model. The bias-dependant simulated STM images reveal that a retraction of the top most dangling bond orbitals is the unique mechanism that enables the STM tip to image the trench structure. This work was funded in part by the National Science Foundation (DMR-9733994) and the Office of Naval Research (N00014-97-1-1058).