Mechanism of solid-state diffusion reaction in vacuum between metal (Fe, Ni, and Co) and 4H–SiC

Experiments were conducted to investigate the vacuum diffusion reactions between 4H–SiC and various metals (iron (Fe), nickel (Ni), and cobalt (Co)). The effects of temperature, time, and metallic materials on the diffusion reactions were systematically analyzed. Notably, a solid-state diffusion reaction between the metal and 4H–SiC was observed at low temperatures, and the mechanism governing the solid-state interface diffusion reaction between the single-crystal 4H–SiC and metals was elucidated. The results indicate that a chemical reaction occurs between the metal and 4H–SiC during solid-state diffusion, leading to the formation of metal silicides under vacuum conditions. The temperature threshold for the solid-state diffusion reaction between 4H–SiC and metals falls within the range of 550–650 °C. Interestingly, the diffusion reaction proceeds without soaking. Furthermore, the metal type significantly influenced the diffusion rate.