螺旋波等离子体增强化学气相沉积氮化硅薄膜

利用螺旋波等离子体增强化学气相沉积(HWP-CVD)技术，以SiH4和N2为反应气体进行了氮化硅(SiN)薄膜沉积，并研究了实验参量对薄膜特性的影响.利用傅里叶变换红外光谱、紫外—可见光谱和椭偏光检测等技术对薄膜的结构、厚度和折射率等参量进行了测量.结果表明，采用HWP-CVD技术能在低衬底温度条件下以较高的沉积速率制备低H含量的SiN薄膜，所沉积的薄膜主要表现为Si—N键合结构.采用较低的反应气体压强将提高薄膜沉积速率，并使薄膜的致密性增加.适当提高N2/SiH4比例有利于薄膜中H含量的降低. 关键词： 螺旋波等离子体 化学气相沉积 氮化硅薄膜

Silicon nitride films prepared by helicon wave plasam-enhanced chemical vapour deposition

Silicon nitride films(SiN) are deposited by helicon-wave plasma-enhanced chemical vapour deposition(HWP-CVD) under the condition that a gas mixture of SiH4 and N2 is required.The influence of experimental parameters on the properties of the sample films is investigated.The parameters such as bond structure,thickness and refractivity of SiN films are measured by using Fourier transform infrared(FTIR) spectroscopy,ultraviolet-visible spectroscopy and ellipsometer detection technique.Results show that SiN films with a low hydrogen content can be prepared by HWP-CVD at a higher rate and lower substrate temperature,and the main bond mode in the deposited SiN films is Si—N stretching mode.At lower reactive gas pressure,the deposition rate is promoted and the density of the sample films increases.The appropriate increase in N2/SiH4 ratio is beneficial to the decrease of the H content in SiN films.