Atomic-Level Investigation of CHx and C2Hx Adsorption on β-SiC (111)‎ Surface for CVD Diamond Growth from DFT Calculations

الملخص EN

The focus of this paper is on the adsorption of unsaturated hydrocarbon molecules on β-SiC (111) surfaces during diamond film growth.

The CHx and C2Hx molecules have been investigated to obtain a specific insight into absorbing diamond processes on the atomic scale.

Structural and electronic properties of CHx and C2Hx adsorption on the Si- and C-terminated surfaces have been studied by first-principles calculations based on density functional theory (DFT).

From the calculated energetics and geometries, we find that C2Hx adsorption on the Si-terminated surfaces has six possible surface reconstructions.

For the C-terminated surface, there exist eight possible surface reconstructions.

Five surface reconstructions, including CH2 adsorption on the Si- and C-terminated surface, CH–CH2 and CH=CH2 adsorption on the C-terminated surface, and C2H5 adsorption on the Si-terminated surface, have the largest hydrogen adsorption energies and more stability of surface reconstructions.

Calculations demonstrate that the Si-terminated surface is energetically more favorable for fabricating CVD diamond coatings than the C-terminated surface.