含氮氟化类金刚石(FN-DLC)薄膜的研究:(Ⅰ)sp结构与化学键分析

Study of FN-DLC thin films:(Ⅰ)sp structure and chemical bond analysis

以CF4,CH4和N2为源气体,利用射频等离子体增强化学气相沉积法,在不同功率下制备了含氮氟化类金刚石膜.用俄歇电子能谱、拉曼光谱、X射线光电子能谱和傅里叶变换红外光谱对薄膜的电子结构和化学键进行了表征,并结合高斯分峰拟合方法分析了薄膜中sp2,sp3结构比率.结果表明,制备的薄膜属于类金刚石结构,不同沉积功率下,薄膜内的sp2/sp3值在2.0—9.0之间,随着沉积功率的增加薄膜内sp2的相对含量增加.膜内主要有C—Fx(x=1,2),C—C,CC和CN等化学键.沉积功率增加,C—C基团增加,膜内F的浓度降低,C—F基团减少,薄膜的关联加强,稳定性提高.

Nitrogen doping of fluorinated diamond-like carbon （FN-DLC） thin films were prepared by radio frequency plasma enhanced chemical deposition （RF-PECVD） under different radio frequency power （RF-power） with CF4, CH4 and nitrogen as source gases. The sp hybrid structure and chemical bond structure of the films were characterized by Auger electron spectroscopy, Raman spectroscopy, X-ray photoelectron spectroscopy and Fourier transform infrared absorption spectrometry, and the sp^2/sp^3 hybrid ratios were analyzed by fitting multi-peaks of Gaussian form. The results show that the thin films are a type of diamondlike carbon films. The sp^2/sp^3 hybrid ratios in the films deposited by different RF-power lie between 2.0 to 9.0. The sp^2 structure in the films increases with the increasing RF-power. The chemical bond structure in the films are C-F, （x = 1,2）, C-C, C-C and C≡N . The C-C bond increases with the increasing RF-power, while the C-F bond decreases. Higher RF-power is shown to reduce the F content in the films. The degree of cross-linking in the films is enhanced and the films become more stable with increasing RF-power.