Infrared analysis of the effect of Ge at the interface between 3C–SiC and Si

Abstract

Several amounts of germanium (Ge) have been deposited at the interface between cubic phase silicon carbide (3C–SiC) thin films and silicon (Si) substrates prior to the carbonization process in order to create a Si pseudo-substrate with modified lattice parameters suitable for epitaxial growth of high quality 3C–SiC. The grown samples have been analyzed by means of infrared spectroscopy. The obtained infrared reflectivity spectra have been accurately modeled with taking into account the contribution of the asperities at the interface. The results showed that one monolayer (ML) of Ge at the interface leads to a strong reduction in the concentration of point defects, an increased mobility, and a significant reduction in the stress at the interface. A statistical simulation of the interface demonstrated that this is due to the fact that 1 ML of Ge at the interface forms thin island-like structures which compensate the lattice mismatch between 3C–SiC and Si and avoid the out diffusion of Si towards the 3C-SiC grown layer.