Chemical Disorder in 6H-SiC Irradiated with Both He and Fe Ions Followed by 1500 °C Annealing: Electron Energy-Loss Spectroscopy Analysis

Abstract

A good understanding of the chemical disorder in silicon carbide (SiC) after ion irradiation is crucial for evaluating structural stability in both semiconductor and nuclear power systems. In this study, 6H-SiC single-crystal was irradiated with 500 keV He and 2.5 MeV Fe ions at room temperature, followed by annealing at 1500 °C for 2 h. The chemical disorders were investigated by electron energy-loss spectroscopy with the transmission electron microscopy at 200 kV. Facetted voids were found in the end region of the damaged layer. Compared with the substrate region, the Si at.% was lower, while the values of C and O at.% were higher, in particular in inner voids. SiCOx (x < 1) bonds at the inner surface of the voids were detected. The energy losses of Si, C edges shifted to be lower in the damaged layer. The possible reason is discussed, and the research results will be used for understanding the ion irradiation-induced damage in SiC.

Keywords

• 6H-SiC
• ion implantation
• chemical disorder
• EELS
• microstructure