Stability of 3C-SiC surfaces under diamond growth conditions

Abstract

The present study deals with the interaction of C-terminated c(2×2) and Si-rich 3×2 3C-SiC (100) reconstructed surfaces with a microwave plasma chemical vapor deposition used for diamond growth. Pure hydrogen and hydrogen/methane exposures have been carried out. Their effects on the atomic ordering and the stoichiometry within the first planes have been studied in situ using low energy electron diffraction and electron spectroscopies: x-ray photoelectron spectroscopy, x-ray Auger electron spectroscopy, and ultraviolet photoelectron spectroscopy. 5min plasma exposures result in a lost of the initial reconstructions, a postplasma oxygen contamination, and strong modifications of the stoichiometry within the first planes. Indeed, the stability of well defined 3C-SiC surfaces depends strongly on their termination: C-terminated surface exhibits a high inertia while the Si-rich surface undergoes partial etching. The three first silicon atomic planes involved in the 3×2 reconstruction are removed upon pure hydrogen plasma while a monolayer is preserved after hydrogen/methane exposure.

In situ study of the initial stages of diamond deposition on 3C–SiC (100) surfaces: Towards the mechanisms of diamond nucleation

“…At the same time, XPS revealed the presence of oxygen at the surface after the CVD exposure, the XPS C 1s/O 1s area ratio is 5.7. This value is close to the one previously measured on C-terminated surfaces after comparable plasma treatment [4]. The binding energy shift disappeared as the oxygen was desorbed after annealing at 1050°C (not shown).…”

“…However, these mechanisms can not be invoked in our study because i) the surface stoichiometry, as determined by XAES, clearly demonstrated a carbon enrichment and ii) our previous experiments [4] showed that the etching by H 2 plasma is negligible for C-terminated 3C-SiC surfaces. Therefore, the formation of anisotropic stripes seems related to atomic surface diffusion processes activated by bombardment of ions with suitable kinetic energy.…”

“…The second one C 2 located at 284 eV is related to carbon atoms lying at the 3C-SiC surface [4]. The XAES C KVV/Si LVV ratio was close to 1.1, i.e.…”

“…Up to now, the mechanisms occurring during the diamond nucleation on 3C-SiC surfaces have been seldom studied [1,2]. Recently, the behaviour of different reconstructed 3C-SiC (100) surfaces after Microwave Plasma (MPCVD) exposure has been investigated [3,4]. Encouraging progress has been made towards highly oriented diamond film preparation on 3C-SiC surfaces [5].…”

Surface Science Contribution to the BEN Control on Si(100) and 3C‐SiC(100): Towards Ultrathin Nanocrystalline Diamond Films

“…[12] This is in fair agreement with the Full Paper XAES C KVV/Si LVV ratio close to that of the C-terminated c(2 Â 2) reconstructed surface. [13] The surface analysis is completed by ex-situ HREELS investigations after annealing at 573 K to desorb contaminants. HREELS is a powerful technique for probing the surface bonds, especially those involving hydrogen.…”