AVS 45th International Symposium
    Surface Science Division Wednesday Sessions
       Session SS1-WeM

Paper SS1-WeM4
Spectromicroscopy Evidence of Lateral Inhomogeneities for Metal-(III-VI) Semiconductor Interfaces

Wednesday, November 4, 1998, 9:20 am, Room 308

Session: Physics of Semiconductors
Presenter: M. Zacchigna, Ecole Polytechnique Federale, Switzerland
Authors: M. Zacchigna, Ecole Polytechnique Federale, Switzerland
H. Berger, Ecole Polytechnique Federale, Switzerland
G. Lorusso, University of Wisconsin, Madison
F Cerrina, University of Wisconsin, Madison
G. Margaritondo, Ecole Polytechnique Federale, Switzerland
Correspondent: Click to Email
We exploited the very high lateral resolution of the MAXIMUM beamline on ALS to study microscopic lateral variations of semiconductor interface barriers. The capability to analyze the chemical properties with high lateral resolution often reveals unexpected overlayer-substratechemical reactions and links between such reactions and lateral barrier inhomogeneities. The experiment first studied lateral band bending changes in metal-semiconductor junctions for several interfaces between Au or Al and different III-VI compounds. By taking photoemission spectra on a series of microscopic spots along the interface is possible to detect the band bending with high lateral resolution. A novel way to perform this type of measurements, giving the "image" of the band bending, will be presented. The second and more interesting part of our study concerns the search for inhomogeneities in the first steps formation of metal-(III-VI) interfaces. We did discover such inhomogeneities in several prototypical interfaces, expanding and corroborating preliminary data on Au-GaSe interface. Furthermore, for the first time we did establish the sought link between barrier fluctuations and local chemical properties