Papers by Author: Charbel Zgheib

Abstract: Ternary (Si_1-xC_y)Ge_x+y solid solutions were grown on Si-face 4H-SiC applying atomic layer molecular beam epitaxy at low temperatures. The grown layers consist of twinned 3C-SiC revealed by cross section electron microscopy. The germanium was incorporated on silicon lattice sites as revealed by atomic location by channeling enhanced microanalysis transmission electron microscopy studies. The Ge concentration of the grown 3C-(Si_1-xC_y)Ge_x+y heteroepitaxial layers decreases with increasing growth temperatures, but exceeds the solid solubility limit.

Abstract: In this paper we present a methodology to affect the stability of polytypes formation during heteroepitaxial growth of SiC on Si. This methodology is based on the investigation of growth related parameters. These parameters involve substrate temperature, effect of impurities on surface diffusion, strain, and super-saturation conditions as solved by using SSMBE growth (Solid Source molecular beam epitaxy).

Abstract: The influence of the growth conditions on the 3C-SiC layer quality in terms of crystallinity, morphology and residual strain was investigated. In dependence on the chosen growth conditions the stress state can be varied between inhomogeneous and homogeneous strain. For the reduction of the residual strain an alternative route for the improvement of the epitaxial growth of 3CSiC( 100) on Si(100) was developed. It consists in covering the silicon wafers with germanium prior to the carbonization step. The achieved improvement in the residual strain and crystalline quality of the grown 3C-SiC layers is comparable to SOI substrates. These beneficial effects were reached by using a Ge coverage in the range of 0.5 to 1 monolayer with respect to the silicon surface.