中文摘要：

采用固源分子束外延（SSMBE）生长技术,用不同的蒸发速率,在Si（111）衬底上生长SiC薄膜。利用反射式高能电子衍射（RHEED）、X射线衍射（XRD）、原子力显微镜（AFM）等实验技术,对生长的样品的形貌和结构进行研究。结果表明,在优化的蒸发速率（1.0 nm·min^-1）下,所生长的薄膜质量最好。低的蒸发速率（0.25 nm·min^-1）难以抑制孔洞的形成,衬底的Si原子可通过这些孔洞扩散到样品表面,导致结晶质量变差。在高的蒸发速率（1.8 nm·min^-1）下,以岛状方式生长甚至以团簇聚集,表面的原子难以迁移到最佳取向的平衡位置,导致样品表面粗糙度变大,薄膜的结晶质量变差,甚至出现多晶。

英文摘要：

The SiC films were grown by solid-source molecular beam epitaxy（SSMBE）at different deposition rates on Si（111） substrate. Its microstructures and properties were characterized with reflection high energy electron diffraction （RHEED）, X-ray diffraction （XRD）, and atomic force microscopy （AFM）. The results show that the deposition rate significantly affects the quality and microstructures of the SiC films. 1.0 nm·min^-1 was found to be the optimized deposition rate,below which,say at a rate of 0.25 nm·min^-1 ,high density of voids form through which Si atoms may easily diffuse; but above which, say at a rate of 1.8 nm·min^-1, coalescence of islands and clusters occur, resulting in high surface roughness, or worse, formation of polycrystalline SiC.