ELECTRON-SPECTROSCOPY INVESTIGATION OF TE THIN-FILMS DEPOSITED AT ROOM-TEMPERATURE ON SI(100)2X1

Ultraviolet and X-ray photoelectron spectroscopies, Auger electron spectroscopy and low energy electron diffraction were used in order to investigate the electronic properties and the growth mode of very thin films of tellurium with mean thickness between 0.5 and 1000 Angstrom deposited at room temperature on a Si(100)2 X 1 surface. The adsorbate-substrate interaction is found to be weak. In the initial stage of the growth the tellurium atoms are chemisorbed on the silicon surface and form a continuous monolayer. The Te 5p valence electrons are involved in order to saturate the Si(100) dangling bonds inducing a 1X1 reconstruction of the surface. Tellurium deposited after the formation of the first continuous layer and up to 10 Angstrom of average thickness, forms 1X1 ordered islands, that is Te deposited at room temperature on Si(100) follows a Stranski-Krastanov growth mode (one layer plus islands). Increasing the amount of Te the islands coalesce and the deposited atoms show a bulk-like behaviour.