Study by TEM and GISAXS of coherent CoSi2 nanoplates buried in Si(100).

KELLERMANN, G.; MONTORO, L.; GIOVANETTI, L. J.; DOS SANTOS CLARO, P.C.; ZHANG, L.; RAMÍREZ. A. J.; REQUEJO, F.G.; CRAIEVICH, A.F.

Congreso; GISAXS 2011; 2011

The development of new procedures for size reduction of components for modern silicon-based integrated circuit (IC) is nowadays an important technological issue. Many authors gave great attention to investigations of self-ordered materials at nanoscale level exhibiting low resistivity and high thermal stability.1-3 Particularly important, not only for fundamental sciences but also for modern silicon-based IC technologies, are the studies of silicon/metal interactions, nucleation processes, atomic diffusion and growth of silicide nanoparticles embedded in silicon matrices. In this work we describe a controlled and reproducible procedure for obtaining very thin hexagonal CoSi2 nanoplates within a Si(100) wafer. A thin silica film containing Co atoms was deposited on the surface of a Si(100) wafer and annealed at 750°C. This thermal treatment was responsible for the formation of spherical Co nanoparticles embedded in the silica film and a few atomic layer thick CoSi2 nanoplatelets within the Si(100) wafer. The morphology, structure and spatial orientation of the CoSi2 nanoplatelets incrusted in the Si crystal were characterized by synchrotron grazing-incidence small-angle x-ray scattering (GISAXS) and transmission electron microscopy (TEM). The experimental results show that the CoSi2 nanoplates have nearly regular hexagonal shape and a uniform thickness. It was also observed that the CoSi2 nanoplate lattice is coherent with the Si lattice and parallel to each one of the four planes of the {111} crystallographic form of the silicon lattice, indicating that the CoSi2 crystals grow with a Si{111} habit plane.