The annealing effect of crystal 4H-SiC films prepared by pulsed laser deposition

SiC films were prepared by pulsed XeCl laser ablation of ceramic SIC target on Si(100) substrate at temperature 850 degrees C and post-deposition high temperature annealing above 1100 degrees C (1100 degrees C< T < 1400 degrees C) in high vacuum (1.3x10(-7) Pa). The surface morphology, crystal structure, composition and chemical state of the element in the films before and after annealing were studied by X-ray diffraction, transmission electron microscopy, scanning electron microscopy, Auger electron Spectrum, X-ray photoelectron spectrum and photoluminescence methods. It was found that the films were consisted of polycrystal 4H-SiC structure before annealing and were turned into singlecrystal epitaxial 4H-SiC after annealing. The surfaces of the films were smooth and the adhesion of films with the substrate was good. The films were transparent. Excited by the laser with wavelength 290 nm at room temperature, the films emitted two luminescence bands with the peaks at 377 nm and 560 nm. The emission at 377 nm was attributed to the combination of the transmission among the valence and conductor bands, while the one at 560 nm was possibly to be from exciton emission.