Scanning tunneling microscopy study of intermediates in the dissociative adsorption of closo-1,2-dicarbadodecaborane on Si(111)

Authors

J.M. Carpinelli, University of Tennessee, Knoxville
E.W. Plummer, Oak Ridge National Laboratory
Dongjin Byun, University of Nebraska-Lincoln
Peter A. Dowben, University of Nebraska-LincolnFollow

Date of this Version

May 1995

Comments

Published in the Journal of Vacuum Science and Technology A 13(3), May/Jun 1995. Copyright © 1995 American Vacuum Society. Used by permission. For free online abstracts, see http://www.avs.org/literature.jvst.b.aspx

Abstract

Closo-1,2-dicarbadodecaborane (C₂B₁₀H₁₂) is a source compound found to be suitable for the deposition of a high resistivity form of boron-carbide (B₅C), and the fabrication of boron-rich semiconductor devices. A scanning tunneling microscope (STM) was used to image these molecular icosahedra on Si(111)-(7 x 7). Molecular decomposition (tip induced and otherwise) produced a boron-carbide/silicon interface with pronounced heterojunction electronic characteristics. In STM, this interface is characterized by a disordering of the Si(111)-(7 x 7) reconstruction. We suggest, based on Auger electron spectroscopy data and low-energy electron diffraction observations, that boron atoms from the dissociated source molecules substitutionally occupy selvedge sites, as in the boron-induced (√3 x √3)R30° reconstruction of Si(111).