Accession Number : ADA310552

Title :   Influence of Surface Defects on Chlorine Chemisorption on Si(100)-(2 x 1).

Descriptive Note : Technical rept.,

Corporate Author : PITTSBURGH UNIV PA DEPT OF CHEMISTRY

Personal Author(s) : Yang, W. ; Dohnalek, Z. ; Choyke, W. J. ; Yates, J. T., Jr

PDF Url : ADA310552

Report Date : 12 JUN 1996

Pagination or Media Count : 30

Abstract : The influence on chlorine chemisorption of surface defects created by low fluence Ar(+) sputtering of the Si(100)-(2x1) surface has been studied. A distinctly different type of Cl bonding is observed on defect sites compared to Cl bonding on Si-Si dimers, as judged by electron stimulated desorption ion angular distribution (ESDIAD) measurements. On the ordered Si(100) surface only terminally bonded Si-Cl species are observed (producing four off-normal Cl(+) beams); on the disordered Si(100) surface an additional Cl(+) beam emitted in the normal direction is present at 120K. This Cl(+) beam is interpreted as a bridge bonded Cl species chemisorbed inside of the dimer vacancy defects. In SiCl2 thermal desorption a new low temperature desorption channel is observed on disordered Si(100) surfaces indicating that defect sites enhance the rate of surface etching. In the range of Ar(+) fluences studied (0.2-5 monolayer) the Cl saturation coverage increases by as much as 30% over that observed on non-defective Si(100)-(2x1).

Descriptors :   *SURFACES, *CRYSTAL DEFECTS, *SILICON, *CHLORINE, *CHEMISORPTION, THERMAL PROPERTIES, ANGLES, IONS, DISTRIBUTION, SITES, ION BEAMS, ETCHING, SATURATION, CHEMICAL BONDS, ELECTRONS, VACANCIES(CRYSTAL DEFECTS), ARGON, DESORPTION, SPUTTERING, DIMERS, ION BOMBARDMENT.

Subject Categories : Inorganic Chemistry
      Physical Chemistry
      Polymer Chemistry
      Crystallography
      Atomic and Molecular Physics and Spectroscopy

Distribution Statement : APPROVED FOR PUBLIC RELEASE