Study on 3C-SiC/Si(111) by X-ray grazing incident diffraction

Monocrystalline 3C-SiC films were successfully grown on Si(111) substrate at substrate temperature of 1000 degrees C by molecular beam epitaxy (MBE) using solid-state element C and Si sources. The RHEED results indicate that the film grown on Si(111) substrate is 3C-SiC film with all cubic axes parallel to the substrate. The quality and the strain of the film were investigated by Synchrotron radiation X-ray grazing incident diffraction method (GID) combining X-ray diffraction (XRD). The result shows that the film is in the state of biaxial tensile strain. The biaxial tensile strain is attributed to the large lattice and thermal expansion coefficient mismatch between SiC and Si. According to the result of the rocking curves of the film at different grazing incident angles, the quality of the film is better in the zone far from the interface between SiC and Si due to the decrease of the defects in the zone far from the interface. The results of rocking curves of GID and XRD show that the tilt mosaic is bigger than the twist mosaic in the SiC film, which indicate that the lattice array in plane is in better order than that in perpendicular direction.