OBSERVATION OF THE INTERFACE OF BA SI(100) BY MDS AND TDS/

Citation
S. Hongo et al., OBSERVATION OF THE INTERFACE OF BA SI(100) BY MDS AND TDS/, Applied surface science, 82-3, 1994, pp. 537-542
Citations number
9
Categorie Soggetti
Physics, Condensed Matter","Chemistry Physical","Materials Science, Coatings & Films
Journal title
ISSN journal
01694332
Volume
82-3
Year of publication
1994
Pages
537 - 542
Database
ISI
SICI code
0169-4332(1994)82-3:<537:OOTIOB>2.0.ZU;2-Q
Abstract
The interaction of Ba overlayers with Si(100)2 x 1 surfaces and barium silicide formation are studied for Ba coverages up to theta = 10 ML b y MDS (metastable deexcitation spectroscopy) and TDS (thermal desorpti on spectroscopy). TDS spectra of Ba from Ba/Si(100) are observed as a function of Ba coverage. The process of Ba dosing on Si(100)2 x 1 and the annealing process are observed by MDS as a function of Ba coverage and as a function of sample annealing temperature, respectively. The work function change is measured as a function of the annealing temper ature simultaneously. It is found from the above experiments that no s ilicide formation takes place by heating up to 800-degrees-C in the sy stem of submonolayer Ba on Si(100)2 x 1 and that silicide is formed ve ry easily by heating up to 250-degrees-C in the system of 2 ML Ba/Si(1 00)2 x 1. The Si-Ba bond is so tight that the Ba atoms bonded to the s ubstrate Si atoms cannot move easily to form three-dimensional barium silicide. Therefore more than a few Ba layers are necessary to form ba rium silicide on the Si(100) surface.