中文摘要：

以一甲基三氯硅烷为先驱体原料（MTS），H2气为载气，采用化学气相沉积（CVD）工艺，在si基体表面制备SiC膜层。利用XPS、XRD、SEM以及HRTEM等表征方法，研究当沉积为SiC＋C时，游离碳对SiC膜层微观结构及其力学性能的影响。结果表明，膜层由SiC和c两相组成，形成SiC／C复合膜层结构，游离碳引起SiC晶粒细化。在SiC／C膜层中，游离碳的石墨化程度低，主要以无定形结构存在于SiC晶粒之间，形成富c区。由于SiC膜层中含有富C区，填充了SiC晶粒之间缺陷，这有利于提高SiC膜层的机械强度，以及改善SiC／Si之间的晶格匹配。

英文摘要：

SiC was deposited on the surface of Si substrate by chemical vapor deposition technique, with methyhrichlorosilane （MTS） as the SiC gaseous source and H2 as carrier gas respectively.The effects of the free carbon on microstructure of SiC film were investigeted by X-ray diffraction（ XPS）, X-ray diffraction（ XRD）, scanning electron microscop（SEM） and high resolution transmis- sion electron microscope（HRTEM） .The results indicate that the SiC/C composite film is consisted of SiC grains and amorphous car- bon mixed some graphite crystallites,which can reduce the grain size of SiC.In addition, the free carbon within SiC film was detected in the gap of SiC grains.The changes in microstrure can increase the mechanical strength of SiC film and improve the SiC/Si crystal lattice matching.