【作者】 刘兴华；

【导师】 蔡从中； 吴卫东；

【作者基本信息】 重庆大学 ， 凝聚态物理学， 2008， 硕士

【摘要】 本文介绍了类金刚石碳（DLC）膜的研究进展,对其结构、表面形貌、性能及沉积机理作了详细的总结、分析和讨论。重点综述了类金刚石碳膜的制备方法、应用背景及研究进展。DLC膜具有极好的力学性能,其高硬度、低摩擦系数及抗磨损性能仅次于金刚石（金刚石的硬度为100GPa）;同时具有高杨氏模量和弹性模量;其次,DLC膜还具有极高的电阻率、电绝缘强度、击穿电压高以及较低的介电常数等;在生物工程方面,DLC膜有其独特的生物兼容性、化学惰性及摩擦学性能。目前,国外已经将DLC膜成功地应用到人工心脏瓣膜、人工关节、人工骨方面。在光学方面,其光致发光率很高,在红外到紫外光波段的吸收系数很小,具有优良的光透过率和光学带隙,在红外区域几乎“透明”。目前,DLC膜已被广泛应用于机械、电子、光学、热学、声学、医学等敏感功能薄膜材料领域,具有良好的应用前景,受到国际科技界的极大关注,如美国已经将DLC膜材料作为国家21世纪的战略材料之一。本文应用低压等离子体增强化学气相沉积（LPPCVD）方法制备类金刚石碳膜,并对其结构和性能进行了研究。通过Raman光谱和XPS光谱确认了薄膜的类金刚石特性,并研究了随制备薄膜的不同工艺参数两种光谱的演变规律,结果发现,改变工艺参数可以很好的调制薄膜中的sp²与sp³的杂化比,制备薄膜中sp³/sp²比例最高可达0.67,sp³含量可达到40.16%,其分子团簇尺寸较小,此时薄膜更加致密。本文研究了主要参量（如源气体流量比、工作气压、射频功率等）对薄膜沉积速率和表面形貌的影响,利用AFM和SEM照片观测了薄膜的表面形貌,通过对分子团簇大小的估算,研究了沉积机理对表面形貌的影响。结果显示,在压强为10Pa,射频功率为10W,氢气流量为0.5sccm,单体流量为0.6sccm条件下可制备出表面平整、致密,均方根粗糙度在1nm左右,沉积速率为11.96nm/min的高光洁度薄膜。利用红外光谱研究了DLC薄膜化学结构,结果显示,制备的薄膜中氢含量较高,薄膜中碳氢原子形成的基团中以sp³CH₃为主且薄膜中没有发现sp²C-H基团。研究表明,T₂B含量少的样品吸收峰强于T₂B含量大的样品,即其含有更多的C=C键。随着气压升高,样品中C=C键的含量下降。射频功率较大时制备的样品吸收峰强于功率较小时制备的样品,即其含有更多的C=C键。研究了工艺参数对薄膜紫外-可见光透射光谱和光学带隙的演变规律。结果表明,薄膜在可见光区域具有良好的透过率,最高可达98%,在紫外波段范围内具有强吸收特性。薄膜的光学带隙在2.328～2.82eV范围。薄膜光学带隙与薄膜的结构有很大关系,特别是与薄膜中sp³杂化键以及C=C双键含量具有直接关系。通过对薄膜的热稳定性研究,发现氢含量过多或者过少都会使薄膜失重较多,只有氢在合适比例情况下才能制备出结构致密的薄膜,同时这也验证了氢在薄膜制备过程中的重要作用。压强较大时制备的薄膜的裂解温度相对较高,裂解吸热量较小。通过改变参数能够得到热稳定性较好的薄膜。因此有理由相信类金刚石碳膜在惯性约束聚变（ICF）实验研究中将有较好的应用前景。更多还原

【Abstract】 In this thesis, the progress on the preparation, structure, surface morphology, and properties of diamond-like carbon （DLC） films were reviewed. DLC films have excellent mechanical properties, high hardness, low coefficient of friction and wear resistance, high Young’s modulus and elastic modulus. DLC films also have high rate of resistance, high electric insulating strength, high breakdown voltage and low dielectric constant. In biological engineering, DLC films performed their own unique biocompatibility. At present, the DLC films have been successfully applied to act as the artificial heart, artificial joints and artificial bone areas. In optical aspects, their high rate of photoluminescence and the weak absorption in the infrared bands made them have an excellent light transmission and optical band gap. At present, they have been widely used in mechanical, electronic, optical, thermal, acoustic, medical areas, etc. DLC films will achieve their bright application prospect, more and more scientists pay attention to the researchs and development of DLC films and releated devices, e.g., the USA has treated the DLC films as a national strategy in the 21st century.The diamond-like carbon films were prepared by using the low-pressure plasma enhanced chemical vapor deposition （LPPCVD） with H₂ and Trans-2-butene as source gases, and their structure and properties were futher studied. Their diamond-like structure was demonstrated by using Raman spectrum and XPS spectrum, and the evolution rules of their Raman spectrum and XPS spectrum under different growth parameters were investigated. The content ratio of sp³ and sp² within the DLC films can be modulated by varying the growth parameters, and its highest value achieved 0.67 whileas the content of sp3 reached to 40.16%.The main work parameters, such as flow ratios of source gases, work pressure and RF power etc, will affect the deposition rate and the surface morphology of DLC films. The surface morphology of DLC films were scanned via AFM and SEM. The results showed that the RMS of DLC films can be optimized to be 1 nm with a deposition rate 11.96 nm / min under the condition of pressure 10 Pa, RF powe 10 W, the hydrogen flow 0.5 sccm and Trans-2-butene flow 0.6 sccm.The FTIR spectrum reveals that the structure and composition of the DLC films varied with the T2B/H2 flow ratios, pressure and RF power. The results show that DLC films we prepared mainly contain sp³C-H bonds whileas the sp²C-H bonds were not found from their FTIR spectrum, the films possess more C=C bonds when they were prepared under lower T2B/H2 flow ratio, or higher RF power, or lower pressure.The UV-VIS spectrum shows that the transmission ratio of the DLC films reaches 98% in the visible light range, the films have strong absorption in the ultraviolet bands, and their optical band gaps vary in the range of 2.328～2.82eV. Its optical band gap has a close relationship with the structure, particularly the content of the sp³ hybrid bonds and the C = C bonds.The thermogravimetric analysis shows that the mass will loss more when excessive or too little hydrogen in the films, the dense DLC films can be deposited with an appropriate proportion of hydrogen. The results also verify the content of hydrogen in the process of preparation films has a great influence on the quality of the DLC films. It is also observed that films deposited under higher pressure have higher cracking temperature. The thermal stability of DLC films can be improved by adjusting the deposition parameters and annealing treatment. It is believed that the diamond-like carbon films will have a better prospect in inertial confinement fusion （ICF） experiment.更多还原