Growth of crystalline SiC film free of cavities by heating PS/silica sol-gel coatings on Si (111) substrate

Single crystalline 6H-SiC films were prepared by spin-coating silica and polystyrene (PS) sol-gel layers subsequently on Si (111) substrate, and then the sample heated in vacuum (10 −3 Pa) to temperature above 1000 °C. The films were investigated by Fourier transform infrared absorption (FTIR), transmission electron diffraction (TED), X-ray diffraction (XRD), and scanning electron microscopy (SEM) measurements. Plan-view SEM observations indicated that the silica layer sandwiched by PS and Si substrate can suppress the interface cavity formation. It was proposed that the silica layer acted as a barrier of out-diffused Si atoms, and took the place of the substrate as the reservoir of Si supply to form SiC during the heat treatment.