含氮氟化类金刚石(FN-DLC)薄膜的研究:(Ⅲ)疏水性能分析

Study on FN-DLC thin films:(Ⅲ) hydrophobic nature analysis

不同沉积条件下,在单晶硅基底上沉积了含氮氟化类金刚石(FN-DLC)薄膜,用静滴接触角/表面张力测量仪测量了水与FN-DLC膜表面的接触角.用X射线光电子能谱、Raman光谱和傅里叶变换吸收红外光谱(FTIR)分析了薄膜的组分和结构.用原子力显微镜观测了薄膜的表面形貌.结果表明,FN-DLC薄膜疏水性能主要取决于薄膜表面的化学结构、薄膜表面极化强度的强弱、以及薄膜的表面粗糙度的大小.sp3/sp2的比值减小,CF2基团含量增加,薄膜粗糙度增加,接触角增大;反之,则接触角减小.在工艺上,沉积温度和功率的减小,气体流量比r(r=CF4/[CF4+CH4])的增加,都会使水的浸润性变差,接触角增大.

Nitrogen doping of fluorinated diamond-like carbon （FN-DLC） films were deposited on p-type （100） silicon wafers at different deposition condition. The contact angle of water on the FN-DLC films surfaces was measured by a sessile-drop method. The surface morphology of films was characterized by atomic force microscopy （AFM）. The Raman spectrum, infrared spectrum and X-my photoelectron spectrum （XPS） demonstrate that the hydrophobic nature of FN-DLC films lies on chemistry structure, polarization intensity and roughness of films surface. As the ratio of sp^3/sp^2 decreases, the quantity of CF2 and roughness of film surface increases, thus contact angle increases. Otherwise, contact angle decreases. The contact angle is correlated with the deposition condition, which low temperature, low radio frequency power and high flux ratio r（ r = CF4/[ CF4 ＋ CH4 ] ） brings the contact angle to ascend.