The surface morphology of Si (100) after carbon deposition

Abstract The concentration of carbon in thin epitaxial layers is thought to be above the solution limit if special epitaxial conditions apply [H. Rucker, M. Methfessel, E. Bugiel, H.J. Osten, Phys. Rev. Lett. B 72 (1994) 3578]. Depending on those conditions the structure and morphology of carbon deposited on Si(100) at 600°C has been studied by means of scanning tunnelling microscopy and low energy electron diffraction. At carbon coverages below 1/2 monolayer (ML) a c(4×4) structure is obtained. Higher carbon coverages (up to 1 ML) give rise to island formation and a 2×1 structure of the substrate surface. The surface morphology of subsequent Si depositions depends on the initial carbon concentration. The c(4×4) structure (without islands) can be observed even after an additional epitaxial Si layer 3 nm thick is deposited. The Si epitaxy on carbon layers with islands leads to a patchwise growth process resulting in surfaces with etch pit-like defects.