Published online by Cambridge University Press: 28 February 2011
We report the growth of structurally continuous, pinhole-free epitaxial YSi2−xfilms on Si(l1l) substrates as thin as 30Å. This is accomplished by depositing both yttrium andsiicon in the appropriate stoichiometric ratio onto substrates held near room temperature, which is apparently below the activation energy for the nucleation of a reaction between a deposited Y film and a Si substrate. Diffusion of Si atoms from an evaporation source into a thin Y layer occurs below this barrier energy, allowing the layer by layer formation of YSi2−x without the removal of silicon from the substrate, maintaining a relatively low interface free energy between the growing silicide film and the Si(lll) substrate. Samples have been annealed to 500-900°C to improve epitaxy without the creation of pinholes. Use of the template method allows for the growth of thicker films also free of pinholes.