Formation of Uniform Solid-Phase Epitaxial CoSi₂ Films by Patterning Method

Abstract

This paper reports that uniform solid-phase epitaxial CoSi 2 films without any holes can be fabricated by patterning the Si(111) substrate in the form of squares or stripes before the CoSi 2 epitaxial growth. The surface energies of the CoSi 2 and Si are considered theoretically. Since the surface energy of the Si(111) surface is smaller than that of the CoSi 2 (111) surface, the film tends to expose the Si substrate, forming holes in the films. The total surface energy on the patterned area is calculated numerically, showing that the film will be uniform if the pattern size is smaller than a certain critical dimension. The numerical calculations agree qualitatively with the experimental results.