蒸发速率对Si衬底上SSMBE外延SiC薄膜的影响  

Effect of Different Deposition Rates on the Growth of SiC on Si by SSMBE

作　　者：刘忠良[1] 刘金锋[1] 任鹏[1] 徐彭寿[1] 

机构地区：[1]中国科学技术大学国家同步辐射实验室,合肥230029

出　　处：《真空科学与技术学报》2008年第4期299-302,共4页Chinese Journal of Vacuum Science and Technology

基　　金：国家自然科学基金(No.50572100)

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。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.

关 键 词：蒸发速率 碳化硅 硅衬底 固源分子束外延 

分 类 号：O484[理学—固体物理] TN304[理学—物理]