ICP-CVD制备氟化非晶碳(a-C：F)薄膜的研究

Growth and Characterization of Amorphous Fluorinated Carbon Films by Inductively Coupled Plasma Chemical Vapor Deposition

本文使用CH2F2为源气体,利用电感耦合等离子体增强化学气相沉积(ICP-CVD)法在不同放电模式(连续或脉冲)、沉积气压、射频功率和位置下制备了a-C∶F薄膜。用原子力显微镜(AFM)观察了薄膜的表面形貌,通过FTIR、XPS对其结构进行了表征。研究结果表明:放电模式、放电气压、射频功率、基底位置均对薄膜的表面粗糙度(RMS)和组成具有重要的影响。在脉冲波模式下,增加放电气压,薄膜RMS值的变化呈现出先降低后升高的变化趋势;基底距离线圈的距离越远,所沉积薄膜的RMS值越小。而在连续波模式下,距离线圈较远的B、C位置薄膜的RMS值却相对较高。增加放电功率导致沉积薄膜的RMS值较小。本文也对CH2F2等离子体进行了发射光谱(OES)诊断研究。结果表明,对比脉冲波模式,连续波放电时等离子体中含碳物种明显减少。结合表征结果和OES结果对薄膜的生长机理进行了探讨。

The amorphous fluorinated carbon （a-C：F） films were deposited by inductively coupled plasma chemical vapor deposition （ICP-CVD）. The microstructures and properties were characterized with atomic force microscopy （AFM）, X-ray photoelectron spectroscopy （XPS） and Fourier transform infrared spectroscopy （FTIR）. The impacts of the film growth conditions, including the discharge mode, pressure, RF power, substrate temperature and substrate position, on the quality of the films were studied. The results show that three factors, including the discharge mode, pressure and substrate position, strongly affect the surface roughness and stoichiometry. For example, with a pulsed RF plasma, as the pressure increases, the root-mean-square （RMS） surface roughness first increases and then decreases;and the farther away the substrate, the smaller the RMS roughness. In contrast, with a continuous RF plasma, the RMS roughness increases with the increase of the separation between the substrate and the coil, but decreases with an increase of the discharge power. Possible mechanisms were tentatively discussed.