Ultrathin Au layers on Si 100/: surface silicide formation at room temperature

The deposition at room temperature of Au films on Si 100. has been studied by a combination of techniques for thicknesses up to 10 monolayers. From low-energy ion scattering LEIS. and Auger electron spectroscopy AES. measurements, it is derived that the outermost layer consists of a mixture of Au and Si for the whole coverage range. The critical coverage to induce intermixing is determined to be at most 0.25 monolayer ML., but the measurements are also consistent with an immediate onset of intermixing. The surface silicide has a disordered character as shown by spot-profile analysis low-energy electron diffraction SPA-LEED.. Using this technique it is also concluded that the interface between the surface silicide and the substrate is essentially identical to the morphology of the Si 100.surface before deposition. q1998 Elsevier Science B.V. All rights reserved