Exploring the interaction mechanisms between oxygen plasma and silicon carbide for non-defect oxidation

Understanding the energy-dependent plasma oxidation mechanism of 4H-SiC is crucial for advancing the development of high-performance devices. However, due to the lack of in-situ characterization techniques and the limitations in precisely controlling the plasma energy during experiments, the reaction mechanism between 4H-SiC and the oxygen plasma at the atomic scale remains unclear. This paper investigates the energy-dependent plasma oxidation mechanism of 4H-SiC using reactive molecular dynamics simulations, revealing four distinct oxidation regimes as the energy increases. In regime I (below 1.2 eV), only Si-O terminals formed on the SiC surface. In regime II (1.2 eV–4.7 eV), carbon is removed as a gaseous product, while silica-like Si-O-Si groups are formed on the surface. In regime III (4.7 eV–30 eV), the Si-O-Si groups begin to be etched, although the number of etched Si-O-Si groups are less than the generated ones, allowing the silica to be retained. Finally, in regime IV (>30 eV), oxygen atoms are implanted in the subsurface of the slab, leading to significant displacement damage. These findings contribute to a further understanding of the plasma oxidation mechanism of SiC and provide scientific guidance for optimizing the plasma oxidation process.