Sequential analysis of diamond nucleation on silicon (001) with bias enhanced nucleation using X-ray photoelectron spectroscopy and reflection high energy electron diffraction investigations

摘要

Diamond synthesis by microwave plasma assisted chemical vapour deposition (MPCVD) with a bias enhanced nucleation (BEN) step constitutes the most efficient method to obtain heteroepitaxy and is also useful to reach high nuclealion densities. In this study, sequential reflection high-energy electron diffraction (RHEED) and X-ray photoelectron spectroscopy (XPS) investigations enabled us to highlight the formation of amorphous carbon and crystalline silicon carbidernon the surface before diamond growth. By varying the bias voltage, we underlined an optimized value corresponding to a higher quantity of amorphous carbon. This quantity is strongly correlated to the diamond nucleation density. As for the quality of the SiC texture, this seems to be directly linked to bias voltage too: low bias voltages enable us to obtain high oriented 3C-SiC whereas high bias voltages lead to a completely misoriented polycrystalline SiC film.