热丝CVD生长SiCN薄膜的研究

在HFCVD系统中采用SiH₄/CH₄/H₂/N₂混合气体成功的制备了SiCN薄膜.SEM照片显示制备的SiCN薄膜由棒状结构构成,而在HRTEM下发现这些棒状结构是由生长在无定型SiCN基体当中的纳米晶粒组成的.进一步的SAED和XRD分析说明SiCN纳米晶粒具有类似于α-Si₃N₄的结构.XPS和FTIR分析表明薄膜中含有Si、C、N和O几种元素以及C=N、Si-N和C-N等共价键,但是并没有观察到C-Si的存在.由实验得出结论,SiCN晶体的生长包括两个步骤:α-Si₃N₄团簇的生长和C取代其中Si的过程.

Silicon Carbon Nitride Films Grown by Hot-Filament Chemical Vapor Deposition

The silicon carbon nitride (SiCN) films were successfully synthesized on silicon substrate using SiH₄/CH₄/H₂/N₂ mixture by hot-filament chemical vapor deposition (HFCVD) without bias. The resultant films consist of many micro-rods with mean diameter about 3μm and lengths up to 35 μm measured by SEM, and the micro-rods are built with blocks of nanocrystalline SiCN grown in amorphous matrix observed by HRTEM. Further SAED and XRD analysis indicate that the structure of SiCN nanocrystal is similar to that of α-Si₃N₄ with small deviations. XPS and FTIR were employed to investigate the compositions of SiCN films, indicating the presence of Si, C, N, O and H, and a chemical bonding network of C=N, N-Si and N-C bonds in SiCN films, but the C-Si bonds absent. From these results, we suggest that the SiCN growth may mainly include two processes: the growth of α-Si₃N₄ clusters and the substitution of Si atoms by C atoms.