Microstructure investigation of SiC films synthesized from liquid phase in Sm–Co melts

Silicon carbide layers were grown on a Si substrate at a temperature below 1100 °C and pressure of 105 Pa. The synthesis was carried out in a tube furnace through cyclic heating process using methane as a carbon source and Sm–Co mixed powder as a solvent. The growth of SiC from rare earth Sm-based solvent is an innovative approach, and Co can promote the formation of solvent during the growth process. The structural and compositional analyses were carried out using X-ray diffraction, electron probe micro-analyzer, scanning electron microscopy and transmission electron microscopy. Results indicated that β-SiC was successfully fabricated on Si (1 1 1) substrate. The heterogeneous nucleation of β-SiC was found to be observed initially at the edge of triangle-shaped sites on Si (1 1 1) surface that formed due to the existence of Co, and then grew and expanded to form β-SiC film. The growth process of SiC via vapour–liquid–solid mechanism was also discussed in this study.

► Successful synthesis of SiC using liquid phase technique below 1100 °C.
► The growth of SiC from rare earth Sm-based solvent is an innovative approach.
► Growth of β-SiC in <1 1 1> direction parallel to Si wafer.
► Appearance of some triangle-shape pits on Si (1 1 1) substrate after decomposition of Co–Si alloy.
► These triangle shaped pits promote the heterogeneous nucleation of SiC.