本文采用四极杆质谱对高速沉积硅薄膜过程中硅烷浓度的变化情况进行了在线监测,针对反应过程中的反向扩散现象进行了研究.结合硅烷耗尽模型的计算,对反应气体的馈入方法进行了优化.结果表明,适当的调整硅烷气体与等离子体起始放电时刻的时间差,可以有效的控制反应过程中硅烷浓度,特别是放电开始瞬间时的条件,从而改善器件的界面特性以及薄膜厚度方向上的纵向结构均匀性. In this paper, the quadrupole mass spectrometry (MS) was used to monitor the concentration of silane during high-speed deposition of silicon thin films, and the phenomenon of reverse diffusion in the reaction process was studied.With the calculation of silane depletion model, The results show that the proper adjustment of the time difference between the initial discharge time of the silane gas and the plasma can effectively control the silane concentration in the reaction process and especially the instant at the start of the discharge so as to improve the interfacial properties of the device and the film Longitudinal structural uniformity in the thickness direction.