中文摘要：

采用CG/MS定性定量分析了MTS/H_2体系CVD SiC的气相组成,考察了沉积温度、总压和流量对气相组成的影响,从反应速率和分子浓度大小的角度出发,分析了MTS在H_2中的分解步骤.主要结论如下：（1）检测到CH_4、C_2H_6、C_2H_4、C_3H_6、C_2H_2、MTS、SiCl_4和CH_3SiHCl_2物质,其中CH_4和SiCl_4的含量较高.（2）体系温度、总压和总流量对气相组成有显著影响,其影响规律与热力分析结果一致.（3）MTS主要以Si-C键断裂引发分解反应,经历与原反应气反应、中间物质和副产物生成等主要阶段,CH_3→C_2H_6→C_2H_4→C_2H_2是生成烷烃化合物的主要路径.

英文摘要：

Qualitative and quantitative analyses were carried out to investigate the effect of the deposition temperature, pressure and flow rate of chemical vapor deposition imposed on the concentrations of MTS/H_2 CVD SiC gaseous species through GC/MS method.Decomposition procedures of MTS in H_2 based on the reaction rate and concentrations of species were analyzed.The results show that：（1） the identified gaseous species are CH_4、C_2H_6、C_2H_4,C_3H_6,C_2H_2,MTS,SiCl_4 and CH_3SiHCl_2,of which the concentrations of CH_4 and SiCl_4 are comparatively higher;（2） temperature,pressure and flow rate have great effect on the concentrations of gaseous species,and their regular patterns follow the same dependence as the thermodynamics;（3） MTS mainly starts with the cracking and decomposition of Si-C,and experiences three stages,the reaction with H_2,the formation of middle objects and also by-products.It is suggested that the main formation route of alkane is CH_3→C_2H_6→C_2H_4→C_2H_2.