红外高效增透膜镀类金刚石膜的特性研究

外层为氟化物的红外高效膜、膜层软、易吸潮和氧化.本文提出使用类金刚石膜做红外高效膜的保护膜,讨论了镀制类金刚石膜后,镀膜件光谱特性的变化情况.     

飞秒激光制备硅窗口增透保护类金刚石膜

采用飞秒激光(800 nm,120 fs,3 W,1 000 Hz)制备类金刚石膜,研究了不同偏压、生长温度和氧气氛等辅助手段对激光沉积类金刚石膜的影响,实验发现在室温(25℃)、无偏压和低气压氧气氛(2 Pa)条件下沉积的类金刚石膜性能最优。在单面预镀普通增透膜的硅红外窗口材料上镀制出了无氢类金刚石膜,3~5μm波段平均透过率达到90%以上,纳米硬度高达40 GPa,用压力为9.8 N的橡皮磨头,摩擦105次,膜层未见磨损,并且通过了军标规定的高温、低温、湿热、盐雾等环境试验,所制类金刚石膜可对红外窗口起到较好的增透保护作用。     

非平衡磁控溅射法类金刚石薄膜的制备及分析

利用非平衡磁控溅射物理气相沉积技术制备了光滑、致密、均匀的类金刚石薄膜.分析沉积工艺参数对所得类金刚石薄膜的电学特性的影响以及溅射粒子的大小、能量、碰撞及沉积过程中的相变机理后认为：溅射粒子越小、与环境气体分子的碰撞次数越多、与衬底相互作用时具有适当动量等，能够有效提高薄膜中sp^３杂化碳原子的含量.利用拉曼光谱 、纳米力学探针、红外光谱、扫描电镜等分析了所得类金刚石膜的结构、力学及光学性能、 表面形貌等特征.结果表明，类金刚石膜中sp^３杂化碳原子的含量较高，显微硬 度大于11GPa，薄膜光学透过率达到89.4％，折射系数为1.952，沉积速率为0.724μm/h，表 面光滑、致密、均匀，不存在明显的晶粒特征. 关键词： 非平衡磁控溅射 类金刚石膜 拉曼光谱 红外光谱     

RF-PECVD法制备大面积类金刚石薄膜性能的研究

采用RF-PECVD法在锗、硅红外光学窗口上制备了大面积(基底直径φ=150～250mm)类金刚石薄膜.采用拉曼光谱分析了大面积DLC膜的结构组成,对RF-PECVD法制备的大面积DLC膜的均匀性、红外光学性能、机械力学性能以及其抗恶劣环境的能力进行了检测和分析.膜层厚度均匀性在3%以内.锗、硅红外窗口双面镀制DLC膜后,极值透过率分别达92%和96%以上,可显著提高红外光学窗口的显微硬度.膜层具有极强的抗盐雾、耐海水腐蚀和抗摩擦的能力.     

脉冲激光沉积无氢钨掺杂类金刚石膜的摩擦与机械性能

采用脉冲激光沉积技术制备出无氢钨掺杂非晶态类金刚石膜.膜中的钨含量与靶材中的钨含量保持稳定的线性关系,显示了脉冲激光沉积在难熔金属掺杂技术方面的亮点.由于碳-钨结构的形成和表面粗糙度影响,膜层的干摩擦系数随着钨含量的增加显现出先减后增的趋势,钨含量为9.67 at.%时达到最低值0.091.钨含量的增大降低了类金刚石膜纳米硬度和杨氏模量,但最佳的膜层耐磨性参数并非表现在硬度最大(52.2 GPa)的纯类金刚石膜中,而是出现在低掺杂含量(6.28 at.%)的类金刚石膜中.研究为脉冲激光沉积技术制备低摩擦、高硬度无氢钨掺杂类金刚石膜的应用提供了技术实践.     

沉积时间对球状微米金刚石聚晶结构的生长及其场发射特性影响

利用微波等离子体化学气相沉积法,在覆盖金属钛层的陶瓷衬底上,通过改变沉积时间制备出不同结构的类球状微米金刚石聚晶碳膜.通过扫描电子显微镜、喇曼光谱、X射线衍射谱对碳膜进行了分析测试,并研究了不同沉积时间下沉积的类球状微米金刚石聚晶薄膜的场致电子发射特性,结果显示:不同的沉积时间所制备的碳膜形貌有很大变化,场致电子发射的...     

脉冲高能量密度等离子体法类金刚石膜的制备及分析

利用脉冲高能量密度等离子体法在光学玻璃衬底上、在室温下成功的制备了光滑、致密、均匀的纳米类金刚石膜.工艺研究表明：放电电压和放电距离以及工作气体种类对纳米类金刚石膜的沉积起着关键作用.利用拉曼光谱、扫描电镜以及电子能量损失谱分析薄膜的形态结构表明：薄膜具有典型的类金刚石特征；纳米类金刚石膜的晶粒尺寸小于20nm甚至为非晶态；类金刚石膜中含有一定量的氮原子，随着沉积能量的升高，氮的含量增大.纳米类金刚石膜的薄膜电阻超过109Ω/cm2.对放电溅射过程进行了理论分析，结果与工艺研究的结论吻合.     

沉积时间对球状微米金刚石聚晶结构的生长及其场发射特性影响

利用微波等离子体化学气相沉积法,在覆盖金属钛层的陶瓷衬底上,通过改变沉积时间制备出不同结构的类球状微米金刚石聚晶碳膜.通过扫描电子显微镜、喇曼光谱、X射线衍射谱对碳膜进行了分析测试,并研究了不同沉积时间下沉积的类球状微米金刚石聚晶薄膜的场致电子发射特性.结果显示:不同的沉积时间所制备的碳膜形貌有很大变化,场致电子发射的效果也有很大不同,从而得出了场增强因子的降低和导电通道的增长是场发射效果变差的主要原因.     

金刚石薄膜的红外椭圆偏振光谱研究

采用红外椭圆偏振光谱对微波等离子体化学气相沉积法（MPCVD）和热丝化学气相沉积法（H-FCVD）制备的金刚石薄膜在红外波长范围（2.5—12.5μm）的光学参数进行了测量.建立了不同的光学模型，且在模型中采用Bruggeman有效介质近似方法综合考虑了薄膜表面和界面的椭偏效应.结果表明，MPCVD金刚石膜的椭偏数据在模型引入了厚度为77.5nm的硅表面氧化层、HFCVD金刚石膜引入879nm粗糙层之后能得到很好的拟合.最后对两种模型下金刚石薄膜的折射率和消光系数进行了计算，表明MPCVD金刚石薄膜的红外 关键词： 金刚石薄膜 红外椭圆偏振光谱 光学参数 有效介质近似     

类球状微米金刚石聚晶膜场发射的稳定性

在覆盖金属钛层的陶瓷上,利用微波等离子体化学气相沉积(MPCVD)法制备出类球状微米金刚石聚晶膜。通过二极管结构测试了聚晶膜的场致电子发射特性,利用扫描电子显微镜、拉曼光谱、XRD分析了场发射前后薄膜的结构和表面形貌的变化。发现在高场、大电流密度的场发射中,对类球状微米金刚石聚晶薄膜中的金刚石聚晶颗粒影响很小,而对金刚石聚晶颗粒间的非晶碳层影响很大。对类球状微米金刚石聚晶变化机理进行了研究。     

Effects of the ion-beam voltage on the properties of the diamond-like carbon thin film prepared by ion-beam sputtering deposition

Diamond-like carbon(DLC) thin film is one of the most widely used optical thin films.The fraction of chemical bondings has a great influence on the properties of the DLC film.In this work,DLC thin films are prepared by ion-beam sputtering deposition in Ar and CH4 mixtures with graphite as the target.The influences of the ion-beam voltage on the surface morphology,chemical structure,mechanical and infrared optical properties of the DLC films are investigated by atomic force microscopy(AFM),Raman spectroscopy,nanoindentation,and Fourier transform infrared(FTIR) spectroscopy,respectively.The results show that the surface of the film is uniform and smooth.The film contains sp2 and sp3hybridized carbon bondings.The film prepared by lower ion beam voltage has a higher sp3 bonding content.It is found that the hardness of DLC films increases with reducing ion-beam voltage,which can be attributed to an increase in the fraction of sp3 carbon bondings in the DLC film.The optical constants can be obtained by the whole infrared optical spectrum fitting with the transmittance spectrum.The refractive index increases with the decrease of the ion-beam voltage,while the extinction coefficient decreases.     

Effect of H2 and O2 plasma etching treatment on the surface of diamond-like carbon thin film

In this study, we investigated the surface properties of diamond-like carbon (DLC) films for biomedical applications through plasma etching treatment using oxygen (O₂) and hydrogen (H₂) gas. The synthesis and post-plasma etching treatment of DLC films were carried out by 13.56 MHz RF plasma enhanced chemical vapor deposition (PECVD) system. In order to characterize the surface of DLC films, they were etched to a thickness of approximately 100 nm and were compared with an as-deposited DLC film. We obtained the optimum condition through power variation, at which the etching rate by H₂ and O₂ was 30 and 80 nm/min, respectively. The structural and chemical properties of these thin films after the plasma etching treatment were evaluated by Raman and Fourier transform infrared (FT-IR) spectroscopy. In the case of as-deposited and H₂ plasma etching-treated DLC film, the contact angle was 86.4° and 83.7°, respectively, whereas it was reduced to 35.5° in the etching-treated DLC film in O₂ plasma. The surface roughness of plasma etching-treated DLC with H₂ or O₂ was maintained smooth at 0.1 nm. These results indicated that the surface of the etching-treated DLC film in O₂ plasma was hydrophilic as well as smooth.     

离子束流后处理对类金刚石薄膜激光损伤特性的影响

类金刚石薄膜激光损伤阈值低,已经严重制约其在红外激光系统中的应用。基于非平衡磁控溅射技术,在硅基底上沉积类金刚石薄膜;采用离子束流后处理技术,用正交实验法确定影响处理效果的主要因素,对已沉积完成的DLC薄膜进行离子束轰击;在不同处理工艺下,观测薄膜样品的光学常数及拉曼光谱,最后进行了激光损伤测试。从测试结果可知,离子束流后处理参数:离子能量1000eV、放电电流30~40mA、轰击时间8min时,透射率由原来的60.65%提高到了65.98%;消光系数在900nm后明显降低,DLC薄膜的激光损伤阈值从0.69J/cm2提高到1.01J/cm2。     

The influence of the structures and compounds of DLC coatings on the barrier properties of PET bottles

To reduce the oxygen transmission rate through a polyethylene terephthalate (PET) bottle (an organic plastic) diamond-like carbon (DLC) coatings on the inner surface of the PET bottle were deposited by radio frequency plasma-enhanced chemical vapour deposition (RF-PECVD) technology with C₂H₂ as the source of carbon and Ar as the diluted gas. As the barrier layer to humidity and gas permeation, this paper analyses the DLC film structure, composition, morphology and barrier properties by Fourier transform infrared, atomic force microscopy, scanning electron microscopy and oxygen transmission rate in detail. From the spectrum, it is found that the DLC film mainly consists of sp³ bonds. The barrier property of the films is significantly relevant to the sp³ bond concentration in the coating, the film thickness and morphology. Additionally, it is found that DLC film deposited in an inductively coupled plasma enhanced capacitively coupled plasma source shows a compact, homogeneous and crack-free surface, which is beneficial for a good gas barrier property in PET bottles.     

脉冲源所镀DLC膜成份的分析

类金刚石薄膜(DLC膜)的成份(主要指sp^3键和sp^2键)是影响薄膜性能如薄膜的机械特性和电阻特性等的重要因素。因此，研究DLC膜的成份是非常必要的。本文介绍用X射线光电子能谱仪(XPS)测量薄膜成份的方法。通过采用脉冲真空电弧离子源研究在各种工艺条件下镀制的DLC膜，发现了影响DLC膜成份的主要因素。     

横向电场下的类金刚石薄膜激光损伤

类金刚石(DLC)薄膜在红外区有很高的透过率,但激光损伤阈值低,严重限制了其应用领域。采用直接在DLC薄膜上沉积Ti电极,基于激光损伤阈值(LIDT)测试平台,用1-on-1零几率损伤法,研究了在不同偏置电场下DLC薄膜损伤阈值及损伤形貌的变化。发现电场强度从0增加到700V/cm,损伤阈值明显增大;进一步增大偏置电场,损伤阈值相对不变。分析认为偏置电场改变了激光辐照DLC薄膜区域的光生载流子漂移速度,减小了DLC薄膜的局部热累积,减缓了薄膜的石墨化进程,提高了DLC薄膜的抗激光损伤阈值。     

电化学方法制备ZnO纳米颗粒掺杂类金刚石薄膜及其场发射性能研究

采用液相电化学沉积技术制备了ZnO纳米颗粒掺杂的类金刚石(DLC)薄膜, 研究了ZnO纳米颗粒掺杂对DLC薄膜场发射性能的影响. 利用X射线光电子能谱、透射电子显微镜、Raman光谱以及原子力显微镜分别对薄膜的化学组成、 微观结构和表面形貌进行了表征. 结果表明: 薄膜中的ZnO纳米颗粒具有纤锌矿结构, 其含量随着电解液中Zn源的增加而增加. ZnO纳米颗粒掺杂增强了DLC薄膜的石墨化和表面粗糙度. 场发射测试表明, ZnO纳米颗粒掺杂能提高DLC薄膜的场发射性能, 其中Zn与Zn+C的原子比为10.3%的样品在外加电场强度为20.7 V/μm时电流密度达到了1 mA/cm². 薄膜场发射性能的提高归因于ZnO掺杂引起的表面粗糙度和DLC薄膜石墨化程度的增加.     

The protective properties of ultra-thin diamond like carbon films for high density magnetic storage devices

With the increase of magnetic storage density, the thickness of the protective diamond like carbon (DLC) film on the surfaces of head and disk is required as thin as possible. In this paper, the structure, mechanical properties and corrosion and oxidation resistance of ultra-thin DLC films are investigated. The ultra-thin DLC films were deposited by using filtered cathodic vacuum arc (FCVA) technique. The exact thickness of the ultra-thin DLC film was determined by high resolution transmission electron microscope (HRTEM). Raman analysis indicates that the ultra-thin DLC film presents ta-C structure with high sp³ fraction. In the wear test, a diamond tip was used to simulate a single-asperity contact with the film surface and the wear marks were produced on the film surface. The wear depths decrease with film thickness increasing. If the film thickness was 1.4 nm or above, the wear depth was much lower than that of Si substrate. This indicates that the ultra-thin DLC film with thickness of 1.4 nm shows excellent wear resistance. Corrosion tests in water and oxidation tests in air were carried out to investigate the diffusion barrier effect of the ultra-thin DLC films. The results show that the DLC film with thickness of 1.4 nm provides adequate coverage on the substrate and has good corrosion and oxidation resistance.     

Surface modification of diamond-like carbon films with perfluorooctyl functionalities and their surface properties

Photolysis of perfluoroazooctane with diamond-like carbon (DLC) films led to the surface modification to introduce perfluorooctyl functional groups, confirmed by means of FT-IR, XPS, Raman and TOF-SIMS measurements. The DLC films modified with fluorine moieties showed reduction of the surface energy evaluated by contact angle to water, as compared with pristine DLC film. The contact angle of chemically modified DLC film is 105°, comparable to that of polytetrafluoroethylene (PTFE). By monitoring with XPS, we found that the results on the value of fluorine/carbon ratio of fluorinated DLC films depending on irradiation time are consistent with those of contact angle. Chemical modification of DLC films with perfluorooctyl functionalities also led to improvement of their frictional properties. The friction coefficient of the modified film is 0.05 under vacuum condition, whereas that of the pristine film shows very high value (>1).     

Study of well adherent DLC film deposited on piezoelectric LiTaO3 substrate

A well adherent diamond-like carbon (DLC) film was deposited on piezoelectric LiTaO₃ substrate using PECVD by inserting SiO₂ interlayer. DLC film was characterized using Raman spectroscopy and AFM. Physical and mechanical properties were measured using XRR, ellipsometry, scratch test and nano-indentation. The DLC film exhibits the characteristics of hydrogenated amorphous carbon and a very smooth surface with a 0.25 nm RMS. Scratch test shows that critical load (L_c) is 18 N, which is good enough for applying DLC film to SAW device. The measured mass density, refractive index, hardness and Young’s modulus of DLC film deposited on LiTaO₃ are comparable to the reported values for hydrogenated amorphous carbon film, irrespective of substrates on which the films were deposited.