Abstract
This study establishes that under conditions of epitaxial Si deposition, embedded Ti-silicide nanostructures undergo shape transitions and migrate upward to the surface during capping with a thin epitaxial Si layer. Many of these structures display a near-hemispherical shape which is attributed to minimization of their surface and interface energies. The density and size of the nanostructures are observed to be temperature-dependent. The buried islands induce inhomogeneous stress profiles on the capping layer surface. Atomic-force micrographs of the islands show square holes at the surface aligned along [110] directions which suggests that the sloping surfaces of the pits approximate to (111) surfaces, and the silicide interface is also facetted to match Si (111) planes. Cross-sectional electron micrographs reveal that many islands display faceting. The observed structural changes can be rationalized in terms of the interplay between thermodynamics and kinetics, solid-state capillarity, and the roughening transition.
Original language | English (US) |
---|---|
Article number | 094304 |
Journal | Journal of Applied Physics |
Volume | 110 |
Issue number | 9 |
DOIs | |
State | Published - Nov 1 2011 |
ASJC Scopus subject areas
- General Physics and Astronomy