基体负偏压对类金刚石涂层结构和性能的影响

采用直流等离子体增强化学气相沉积技术(DC-PECVD),通过控制基体负偏压的变化在YG8硬质合金基体上制备一系列类金刚石涂层。选用扫描电子显微镜、原子力显微镜、拉曼光谱、X射线光电子能谱、粗糙度仪对涂层形貌和结构进行表征测试。同时,利用显微硬度计、划痕测试仪系统地分析涂层的显微硬度和界面结合性能。结果表明:随着负偏压增大,涂层表面形貌逐渐平整光滑、致密,颗粒尺寸减小及数量降低。拉曼光谱表明,涂层具有典型的类金刚石结构,涂层中sp3键含量呈先增大后减小趋势,最大值约67.9%出现在负偏压为1000V左右,负偏压过大导致sp3键含量降低。显微硬度随负偏压变化规律与sp3键基本相符,sp3键含量决定显微硬度值大小。负偏压过大对吸附离子产生反溅射作用导致涂层厚度减小。当负偏压为1100V时,涂层与基体间的界面结合性能最优。     

钼薄膜的制备、力学性能和磨损性能

采用直流磁控溅射技术在GCr15轴承钢底材上沉积了钼薄膜。利用XRD，AFM对不同负偏压下沉积的钼薄膜的结构和表面形貌进行了表征；利用纳米压痕仪对薄膜的硬度和膜基结合强度进行了测定；最后利用DF-PM型动静摩擦系数精密测定仪和扫描电镜(SEM)研究了薄膜的硬度、残余模量与负偏压的关系。结果表明：利用直流磁控溅射法制备的钼薄膜的硬度随负偏压的变化存在最大值，另外负偏压还影响薄膜的微结构、粗糙度以及膜基结合力，但负偏压的改变对钼薄膜的摩擦系数影响不大。     

脉冲负偏压对直流磁控溅射碳膜结构和性能的影响

通过直流磁控溅射技术在基体(硅片、高速钢、钢片)上沉积碳膜。保持其它工艺参数基本恒定,探究薄膜在100V-400V脉冲负偏压下,结构和性能的变化规律。实验结果表明,这种碳膜为非晶态硬质薄膜,具有较好表面形貌,且随着脉冲偏压数值的逐渐增加,其厚度、沉积速率和硬度均呈现先增大后减小的趋势,而摩擦系数则先减小后增大。当脉冲负偏压为200 V时,薄膜具有最佳的力学性能。     

射频—直流等离子体增强化学气相沉积设备的研制

综合利用射频和直流辉光放电的特点研制成功射频－直流等离子化学气相沉积设备。成功地用该设备制备出类金刚石薄膜。类金钢石薄膜的沉积速率随极板负偏压、气体工作压力的增加而增大。     

类金刚石薄膜内应力的测试

采用射频-直流等离子增强化学气相沉积法制备出类金刚石薄膜,用弯曲法测定薄膜的内应力。结果表明,类金刚石薄膜中存在1～4.7GPa的压应力,沉积工艺对薄膜的内应力有很大的影响,薄膜的内应力随极板负偏压的升高而降低,陆C_2H_2气体含量的增加而增大。     

极板负偏压对类金刚石薄膜性质的影响

用射频－直流辉光放电系统制备类金刚石薄膜，研究了极板负偏压（Ｖ）对类金刚薄膜性质的影响。结果表明，类金刚石薄膜的性质明显依赖于极板负偏压，在所研究的范围（－３００－９００Ｖ）内，随Ｖ绝对值的增加，薄膜的折射率，消光系数，生长速率，及硬度增加，电阻率下降，Ｖ的变化使膜中Ｈ一及ｓｐ＾３／ｓｐ＾２的比例发生变化，从而使膜的性质发生变化。     

直流/射频耦合反应磁控溅射法类金刚石薄膜的制备与分析

采用直流/射频耦合反应磁控溅射法在Si(111)衬底上使用高纯石墨靶材制备出了类金刚石(DLC)薄膜。分别采用表面轮廓仪、激光拉曼光谱、傅里叶变换红外光谱、X射线光电子能谱、扫描电镜、白光干涉仪、纳米压痕对薄膜的性能进行了表征和分析。研究了沉积过程中不同工作气压(0.35~1.25Pa)对薄膜沉积速率、结构、表面形貌及力学性能的影响。研究表明,随着工作气压的升高,薄膜的沉积速率逐渐减小,薄膜中sp3含量先升高后降低;薄膜表面粗糙度随工作气压的升高呈现出先降低后升高的趋势,且在工作气压为1.0Pa时达到最小值6.68nm;随着工作气压的升高,薄膜的显微硬度与体弹性模量先升高后降低,且在工作气压为1.0Pa时分别达到最大值11.6和120.7GPa。     

基体负的低偏压对氟化非晶态碳膜结构及性能的影响

为了研究基体负的低偏压Vb对氟化非晶态碳膜的结构、纳米硬度和疏水性能的影响,采用等离子体浸没与离子注入装置,CF4和CH4作为气源,在不同的基体偏压下制备了一系列氟化非晶态碳膜.使用XPS、ATR-FTIR和Raman谱对其成份和结构进行了表征.薄膜硬度通过纳米压痕仪进行测量,采用躺滴法测量薄膜与双蒸水之间的接触角来评价其疏水性能.XPS和FTIR结果表明薄膜中存在C-CF、C-Fx基团.Raman谱结果表明:随着基体偏压的增加,薄膜从类聚合物状结构逐渐转变为类金刚石结构,薄膜的硬度逐渐增加.接触角测量结果表明:在低偏压范围内,单纯地依靠调节偏压并不能显著地提高薄膜的疏水性能.     

类金铡石薄膜内应力的测试

采用射频－直流等离子增强化学气相沉积法制备出类金刚石薄膜，用弯曲法测定薄膜的内应力。类金刚石薄膜中存在１－４．７ＧＰａ的压应力，沉积工艺对薄膜的内应力有很大影响，薄膜的内应力随极板负偏压的升高而降低，随Ｃ２Ｈ２气体一的增加而增大。     

基体偏压对中频磁控溅射沉积DLC膜结构的影响

利用中频非平衡磁控溅射技术,以氩气和甲烷混合气体为工作气体,在载玻片和单品硅片上沉积含氢的类金刚石簿膜.改变加载在基体上的负偏压,在0～400 V范围内,制备5种偏压值下的薄膜,研究偏压对薄膜结构的影响.用光学显微镜和AFM考察薄膜的光学形貌;激光Raman谱定性分析膜的化学组分;VFIR分析其C-H键合类型;纳米压痕法测量膜的硬度.结果表明:当基体上施加偏压-100 V时,可以有效地提高沉积粒子与基体结合力以及溥膜的致密性,薄膜中正四面体的sp3结构和sp3CHn含最增加,纳米硬度提高.     

Effect of bias voltage on growth property of Cr-DLC film prepared by linear ion beam deposition technique

Cr-containing diamond-like carbon films were deposited on silicon wafers by a combined linear ion beam and DC magnetron sputtering. The influence of the bias voltage on the growth rate, atomic bond structure, surface topography and mechanical properties of the films were investigated by SEM, XPS, Raman spectroscopy, AFM, and nano-indentation. It was shown that the chromium concentration of the films increased with negative bias voltage and that a carbide phase was detected in the as-deposited films. The surface topography of the films evolved from a rough surface with larger hillocks reducing to form a smoother flat surface as the bias voltage increased from 0 to −200 V. The highest hardness and elastic modulus were obtained at a bias voltage of about −50 V, while the maximum sp³ bonding fraction was acquired at −100 V. It was suggested that the mechanical properties of the films not only depended on the sp³ bonding fraction in the films but also correlated with the influence of Cr doping and ion bombardment.     

Improving hardness of biomedical Co-Cr by deposition of dense and uniform TiN films using negative substrate bias during reactive sputtering

This paper reports the deposition of a fully dense and uniform TiN film to improve the surface hardness of Co-Cr, particularly, by applying a negative substrate bias during reactive direct current (DC) sputtering. As the TiN film was deposited with a negative substrate bias voltage of 150 V, the microstructure of the films was shifted from a columnar to non-columnar one that was observed to have a dense, uniform and smooth surface. In addition, the preferred orientation was the (111) plane when the films were deposited with a negative substrate bias; however, the (200) plane when they were deposited without a substrate bias. The deposition of the dense and uniform TiN film resulted in a significant increase of the hardness of the Co-Cr. The TiN-deposited Co-Cr with a negative substrate bias showed a very high hardness of 44.7 ± 1.7 GPa, which was much higher than those of the bare Co-Cr (4.2 ± 0.3 GPa) and TiN-deposited Co-Cr without a negative substrate bias (23.6 ± 2.8 GPa).     

The effect of direct current bias on the characteristics of Cu/C:H composite thin films on poly ethylene terephthalate film prepared by electron cyclotron resonance-metal organic chemical vapor deposition

Cu/C:H composite films were prepared on poly ethylene terephthalate (PET) substrate at room temperature by the electron cyclotron resonance-metal organic chemical vapor deposition (ECR-MOCVD) coupled with a negative direct current (DC) bias system. The negative DC bias voltage applied around the substrate strongly affected the crystallographic structure and composition as well as the surface roughness of the copper films. The surface resistivity of films decrease sharply as the bias voltage increase up to about 5 μΩ-cm below which the resistivity remains almost constant in the range of − 900 to − 1700 V. Thus, the bias voltage appeared to be a critical deposition parameter for preparing copper films with low resistivity. With interfacial studies of Cu-PET, copper atoms are embedded into the polymer substrate during the growth process. Therefore, Cu/C:H composite films on PET with good interfacial properties could be prepared by ECR-MOCVD coupled with a (−)DC bias system.     

Properties of zirconium oxide films prepared by filtered cathodic vacuum arc deposition and pulsed DC substrate bias

Thin films of zirconium dioxide have been deposited onto glass and silicon substrates using filtered cathodic vacuum arc deposition under a pulsed negative DC bias. The properties of the films have been investigated using X-ray diffraction, X-ray photoelectron spectroscopy, microhardness testing and optical analysis. It was found that the crystalline phase of the films was strongly influenced by the applied bias and that an amorphous-monoclinic transition occurred on glass substrates for bias values > 250 V. The changes in crystallinity also resulted in an increase in the optical refractive index from 2.09 to 2.22 at 550 nm. A similar behaviour in the variation of the microhardness with applied pulsed DC bias was also observed, where the hardness increased from 11 GPa to 16. 5 GPa.     

Influence of negative voltage on the structure and properties of DLC films deposited on NiTi alloys by PBII

Diamond-like carbon (DLC) films have been successfully deposited on Ti-50.8 at.%Ni using plasma based ion implantation (PBII) technique. The influences of the pulsed negative bias voltage applied to the substrate from 12 kV to 40 kV on the structure, nano-indentation hardness and Young’s modulus are investigated by the X-ray photoelectron spectroscopy (XPS) and nano-indentation technique. The results show that C 1s peak depends heavily on the bias voltage. With the increase of bias voltage, the ratio of sp²/sp³ first decreases, reaching a minimum value at 20 kV, and then increases. The DLC coating deposited at 20 kV shows the highest hardness and elastic modulus values as a result of lower sp²/sp³ ratio. The corrosion resistance of specimen deposited under 20 kV is superior to uncoated NiTi alloy and slightly better than those of the other samples deposited at 12 kV, 30 kV and 40 kV.     

衬底偏压对四面体非晶碳膜结构和性能的影响

采用过滤阴极真空电弧技术并施加一定的衬底负偏压,在P(100)单晶硅片上制备出四面体非晶碳薄膜利用可见光Raman光谱研究薄膜的结构,通过BWF函数描述的单斜劳伦兹曲线拟合数据并获得表征曲线非对称性的耦合系数,从而反映了薄膜中sp3杂化的含量分别用原子力显微镜和纳米压入仪研究薄膜的表面形态和力学性能.结果表明:当衬底偏压为-80V时,薄膜中sp3杂化的含量最多,均方根表面粗糙度值最低(Rq=0.23nm),硬度、杨氏模量和临界刮擦载荷也最大,分别为51.49GPa、512.39GPa和11.72mN.随着衬底偏压的升高或降低,sp3键的含量减少,其它性能指标也分别降低.     

Effect of impinging ion energy on the substrates during deposition of SiOx films by radiofrequency plasma enhanced chemical vapor deposition process

Radiofrequency (13.56 MHz) plasma enhanced chemical vapor deposition process is used for deposition of SiO_x films on bell metal substrates using Ar/hexamethyldisiloxane/O₂ glow discharge. The DC self-bias voltage developed on the substrates is observed to be varied from − 35 V to − 115 V depending on the RF power applied to the plasma. Plasma potential measurements during film deposition process are carried out by self-compensated emissive probe. The deposited films are characterized by Raman spectroscopy, X-ray photoelectron spectroscopy (XPS), nanoindentation, nano-scratch test and thermogravimetric analysis. The characterization results show strong dependency of the SiO_x films properties on the energy of the ions impinging on the substrates during deposition. Analysis of Raman spectra indicates an increase in vitreous silica content and reduction in defective Si-O-Si chemical structure in the deposited SiO_x films with increasing ion energy impinging on the substrates. The increase in inorganic (Si and O) content in the SiO_x films is further confirmed from XPS analysis. The growth of SiO_x films with more inorganic content and defect free chemical structure apparently contribute to the increase in their hardness and scratch resistance behavior. The films show higher thermal stability as the energy of the ions arriving at substrates increases with DC self-bias voltage. The possibility of using SiO_x films for surface protection of bell metal is also explored.     

Nanoindentation and atomic force microscopy measurements on reactively sputtered TiN coatings

Titanium nitride (TiN) coatings were deposited by d.c. reactive magnetron sputtering process. The films were deposited on silicon (111) substrates at various process conditions, e.g. substrate bias voltage (V_B) and nitrogen partial pressure. Mechanical properties of the coatings were investigated by a nanoindentation technique. Force vs displacement curves generated during loading and unloading of a Berkovich diamond indenter were used to determine the hardness (H) and Young’s modulus (Y) of the films. Detailed investigations on the role of substrate bias and nitrogen partial pressure on the mechanical properties of the coatings are presented in this paper. Considerable improvement in the hardness was observed when negative bias voltage was increased from 100–250 V. Films deposited at |V _B| = 250 V exhibited hardness as high as 3300 kg/mm². This increase in hardness has been attributed to ion bombardment during the deposition. The ion bombardment considerably affects the microstructure of the coatings. Atomic force microscopy (AFM) of the coatings revealed fine-grained morphology for the films prepared at higher substrate bias voltage. The hardness of the coatings was found to increase with a decrease in nitrogen partial pressure.     

On the dependence on bias voltage of the structural evolution of magnetron- sputtered nanocrystalline Cu films during thermal annealing

The nanostructural evolution during heat treatments of DC magnetron-sputtered Cu films deposited at different substrate bias voltages was experimentally studied. A growth chamber equipped with two magnetrons and Kapton windows for in-situ X-ray diffraction was mounted on a six-circle goniometer at a synchrotron beam line. Using Bragg-Brentano X-ray diffraction, the grain size, the texture, and the lattice constant were monitored during thermal annealing. Increasing the substrate bias voltage, the grain growth rate lowered, and the change in texture with time became smaller due to a decrease in the defect concentration. Furthermore, the grain size in the as-deposited films decreased with increasing bias voltage. The activation energy for grain growth was, within experimental errors, the same in all the films.