靶电流对非平衡磁控溅射制备无氢碳膜结构与性能的影响

利用非平衡磁控溅射(UBMS)技术在硅基片上制备了无氢碳膜,并采用Raman光谱、X射线衍射、傅立叶变换光谱等手段对不同靶电流下沉积的薄膜的微观结构、沉积速率、粗糙度、表面接触角及红外透过率进行了研究.试验结果表明:随着靶电流的增大,薄膜的沉积速率增大,薄膜中sp3键含量增加,薄膜表面接触角增大,红外透过率增大;而薄膜的粗糙度随靶电流增加而减小.靶电流是影响非平衡磁控溅射制备无氢碳膜结构与性能的1个主要因素.     

Effect of hydrogen flow on the properties of hydrogenated amorphous carbon films fabricated by electron cyclotron resonance plasma enhanced chemical vapor deposition

The hydrogenated amorphous carbon films (a-C:H, so-called diamond-like carbon, DLC) have exceptional physical and mechanical properties and have wide applications. In the present study, amorphous hydrogenated carbon films (a-C:H) have been deposited on a Si (100) substrate at different hydrogen flow using electron cyclotron resonance chemical vapor deposition (ECR-CVD). The flow of hydrogen changed from 10 sccm to 40 sccm and the flow of acetylene was fixed at 10 sccm. The microstructure and properties of the a-C:H were measured using visible Raman spectra, Fourier transform infrared (FTIR) spectroscopy, UV-VIS spectrometer,surface profilometer and nano-indentation. The results showed that the sp³ content and sp³-CH₂ structure in the amorphous hydrogenated carbon films increased with the hydrogen flow. The deposition rate decreased with the hydrogen flow. The residual stress and the nano-hardness of the amorphous hydrogenated carbon films increased with the hydrogen flow. Consequently, the a-C:H film become more diamond-like with the increase of hydrogen flow.     

Diamond like carbon films as a protective surface on PMMA for biomedical applications

Diamond like carbon films are deposited on PMMA using the Radio Frequency Plasma Enhanced Chemical Vapour Deposition technique with the variation of RF power at a constant pressure of 5 × 10⁻² mbar. Acetylene diluted with argon is used as a precursor for the deposition of DLC films. Deposited films are characterized using Raman, FTIR, optical contact angle technique and AFM. Optical contact angle is measured with water and blood of mice. It has been found that DLC coated PMMA is more hydrophobic compared to an uncoated surface. Samples are soaked with simulated body fluid for 30 days for the assessment of biocompatibility. Surface morphology of the samples before and after interaction with simulated body fluid has been studied by using AFM. The haemolysis test has also been carried out for the haemocompatibility assessment.     

Diamond-like carbon thin films produced by femtosecond pulsed laser deposition of fullerite

Diamond-like carbon films have been deposited from a fullerite target by ultra-short pulsed laser deposition technique. The results indicate that the films morphology and structure, determined by scanning electron microscopy, atomic force microscopy and energy dispersive X-ray diffraction, depend strongly on the substrate temperature. X-ray photoelectron, X-ray Auger electron, Raman and surface enhanced Raman scattering spectra indicate that the fs-DLC films composition involves a mixed sp, sp² and sp³ carbon network consisting of aromatic rings and sp³ diamond-like structures linked by chains of different lengths and composition. The films deposited at room temperature, presenting the higher content of sp³ carbon (48%), also contain C₆₀ crystalline phase and show a very high hardness of 49 GPa.     

Microstructure and tribological properties of the a-C:H films deposited by magnetron sputtering with CH4/Ar mixture

Hydrogenated amorphous carbon (a-C:H) films were deposited on steel and silicon wafers by unbalanced magnetron sputtering under different CH₄/Ar ratios. Microstructure and properties of the a-C:H films were investigated via Fourier transform infrared spectroscopy (FTIR), Raman spectroscopy, Atomic force microscopy (AFM) and substrate curvature method. The results revealed that CH₄/Ar ratio played an important role in the H content but acted a little function on the sp³/sp² ratio of the films. Also, the internal stress of those films was relatively low (< 1 GPa), and the deposition rate decreased firstly and then increased with the decrease of the CH₄ fraction. The film deposited under CH₄/Ar = 1/1 (55 sccm/55 sccm) with moderate sp³ C-H / sp³ C-C had the best tribological properties. The composition, microstructure and properties of the a-C:H films were strongly dependent on the deposition process and composition of reactant gases.     

Characterization and analysis of DLC films with different thickness deposited by RF magnetron PECVD

Diamond-like carbon (DLC) films have excellent mechanical and chemical properties similar to those of crystalline diamond giving them wide applications as protective coatings. So far, a variety of methods are employed to deposit DLC films. In this study, DLC films with different thicknesses were deposited on Si and glass substrates using RF magnetron PECVD method with C4H10 as carbon source. The bonding microstructure, surface morphology and tribological properties at different growing stages of the DLC films were tested. Raman spectra were deconvoluted into D peak at about 1370 cm-1 and G peak around 1590 cm-1, indicating typical features of the DLC films. A linear relationship between the film thickness and the deposition time was found, revealing that the required film thickness may be obtained by the appropriate tune of the deposition time. The concentration of sp3 and sp2 carbon atoms in the DLC films was measured by XPS spectra. As the films grew, the sp3 carbon atoms decreased while sp2 atoms increased. Surface morphology of the DLC films clearly showed that the films were composed of spherical carbon clusters, which tended to congregate as the deposition time increased. The friction coefficient of the films was very low and an increase was also found with the increase of film thickness corresponding to the results of XPS spectra. The scratch test proved that there was good bonding between the DLC films and the substrates.     

Deposition of diamond-like films of hydrogenized carbon

Diamond-like films of hydrogenized carbon on metal substrates were produced by deposition from methane activated by capacitive electric discharge (AD) within the frequency range of 5–250 Hz and with a relative pulse duration of the charge of 1.5–17. Variations in the charge parameters (frequency, relative pulse duration, current density, methane pressure, the value of gas flow), substrate temperature, and geometry of the vacuum chamber affect the deposition rate, properties, and structures of films within a wide range. Diamondlike films of hydrogenized carbon represented nanocomposite material. The size of sp ² clusters was 5–6 nm, whereas the sp ³/sp ² ratio of carbon and the content of bound hydrogen decreased with increasing substrate temperature and current density and decreasing methane pressure.     

Effect of applied dc bias voltage on composition, chemical bonding and mechanical properties of carbon nitride films prepared by PECVD

Carbon nitride films were deposited on Si (100) substrates using plasma-enhanced chemical vapor deposition (PECVD) technique from CH4 and N2 at different applied dc bias voltage. The microstructure, composition and chemical bonding of the resulting films were characterized by Raman spectroscopy, Fourier transform infrared spectroscopy (FTIR), X-ray photoelectron spectroscopy (XPS) and X-ray diffraction (XRD). The mechanical properties such as hardness and elastic modulus of the films were evaluated using nano-indentation. As the results, the Raman spectra, showing the G and D bands, indicate the amorphous structure of the films. XPS and FTIR measurements demonstrate the existence of various carbon-nitride bonds in the films and the hydrogenation of carbon nitride phase. The composition ratio of N to C, the nano-hardness and the elastic modulus of the carbon nitride films increase with increasing dc bias voltage and reach the maximums at a dc bias voltage of 300 V, then they decrease with further increase of the dc bias voltage. Moreover, the XRD analyses indicate that the carbon nitride film contains some polycrystalline C3N4 phase embedded in the amorphous matrix at optimized deposition condition of dc bias voltage of 300 V.     

Synthesis of nanocrystalline nickel-zinc ferrite (Ni0.8Zn0.2Fe2O4) thin films by chemical bath deposition method

The nickel-zinc ferrite (Ni_0.8Zn_0.2Fe₂O₄) thin films have been successfully deposited on stainless steel substrates using a chemical bath deposition method from alkaline bath. The films were characterized by X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM), static water contact angle and cyclic voltammetry measurements. The X-ray diffraction pattern shows that deposited Ni_0.8Zn_0.2Fe₂O₄ thin films were oriented along (3 1 1) plane. The FTIR spectra showed strong absorption peaks around 600 cm⁻¹ which are typical for cubic spinel crystal structure. SEM study revealed compact flakes like morphology having thickness ∼1.8 μm after air annealing. The annealed films were super hydrophilic in nature having a static water contact angle (θ) of 5°.The electrochemical supercapacitor study of Ni_0.8Zn_0.2Fe₂O₄ thin films has been carried out in 6 M KOH electrolyte.The values of interfacial and specific capacitances obtained were 0.0285 F cm⁻² and 19 F g⁻¹, respectively.     

Corrosion protection of ultra-thin ta-C films for recording slider applications at varied substrate bias

Ultra-thin tetrahedral amorphous carbon (ta-C) films have been prepared by filtered catholic vacuum arc system for recording slider applications. In order to study the corrosion behavior of the slider coatings deposited at different substrate bias, the micro-structure and surface properties of the ta-C films were respectively investigated in terms of Raman spectroscopy, atomic force microscopy, water contact angle and corrosion measurements. Results showed that a very smooth ta-C film with lowest surface energy and highest sp³ bonding content was obtained at the medium bias voltage of 100 V. However, as to the protection against corrosion, the optimum bias was found to be greater than that giving the maximum diamond-like properties.     

含铁类金刚石薄膜的润湿性能和抗腐蚀行为

目的通过直流反应磁控溅射系统在304不锈钢基体上成功制备了含铁类金刚石薄膜,并研究该含铁类金刚石薄膜的润湿性及抗腐蚀行为。方法通过扫描电镜、拉曼光谱仪、原子力显微镜,分别对含铁类金刚石薄膜的结构和形貌进行分析,利用静态接触角测量分析了所制备薄膜的润湿性,且采用动电位极化对有无薄膜沉积的不锈钢体系进行了腐蚀行为测试。结果所制备薄膜具有典型的类金刚石的非晶结构。随着制备过程中甲烷流量的减小,薄膜中sp~3碳含量降低,薄膜致密度逐渐降低。随着甲烷流量的降低,薄膜表面的疏水性能逐渐减小,且自腐蚀电位向负向偏移,腐蚀电流密度逐渐增大。结论含铁类金刚石薄膜能明显提高不锈钢表面的疏水性能和抗腐蚀性能。     

Effect of laser fluences on the structure of carbon nitride films deposited by direct current plasma assisted pulsed laser ablation

Carbon nitride films were deposited by direct current plasma assisted pulsed laser ablation of a graphite target under a nitrogen atmosphere at room temperature. The surface morphology, composition and bonding structure of the deposited films were characterized by atomic force microscopy (AFM), Fourier transform infrared (FTIR) spectroscopy, Raman, and X-ray photoelectron spectroscopy (XPS). The effect of laser fluences in the range 0.5–3 J/cm² on the surface morphology, composition and bonding structure of the carbon nitride films were systematically studied. As laser fluence is increased, AFM results show a great decrease in the surface roughness of carbon nitride films. FTIR and XPS results indicate an increase in the N/C ratio and the content of N atoms bonded to sp³ C, as well as a decrease in the content of H atoms and the content of N atoms boned to sp² C in the deposited films, and Raman spectra indicate an increase in the content of disordered sp² C atoms and the sp² cluster size. The increase in the film density and the decrease in the particle fraction contribute to the decrease of surface roughness with increasing laser fluence.     

Corrosion behavior of nitrogen doped diamond-like carbon thin films in NaCl solutions

Nitrogen doped tetrahedral amorphous carbon (ta-C:N) thin films were grown on p-Si(1 1 1) substrates using filtered cathodic vacuum arc (FCVA) deposition by varying nitrogen flow rate. The effect of nitrogen flow rate on the corrosion performance of the films was investigated through potentiodynamic polarization and immersion tests in 0.6 M NaCl solutions. The polarization results showed that the corrosion resistance of the films dropped with increased nitrogen flow rate due to formation of more sp² bonds. The immersion tests revealed that the pH value of the solutions had a significant effect on the corrosion behavior of the ta-C:N films.     

不同衬底上纳米晶WO3薄膜的光致发光特性

以偏钨酸铵为钨源,聚乙二醇(PEG)为聚合物合成前驱体溶胶,分别在FTO导电玻璃、石英玻璃和石墨衬底制备WO3薄膜,利用X射线衍射(XRD)、拉曼光谱(LRS)和场发射扫描电镜(FESEM)等手段对薄膜进行结构表征,研究衬底和热处理温度对WO3薄膜光致发光性能的影响,并探讨二者对WO3薄膜光致发光性能的影响机制.结果表明:随着热处理温度的升高,WO3薄膜光致发光性能显著提高;在相同热处理温度下,石墨衬底WO3薄膜具有最强的光致发光性能.     

梯度基体温度法和反应溅射TiC过渡层对钛合金基体沉积金刚石薄膜的影响

以H2和CH4作为反应气体,采用热丝化学气相沉积法(HFCVD)在钛合金(Ti6Al4V)平板基体上制备金刚石薄膜,利用扫描电镜(SEM)、X射线衍射仪(XRD)、激光拉曼光谱(Raman)和洛氏硬度仪分析薄膜的表面形貌、结构、成分和附着性能,研究了高温形核-低温生长的梯度降温法对原始钛合金和反应磁控溅射TiC过渡层的钛合金表面沉积金刚石薄膜的影响。结果表明:原始基体区和TiC过渡层区沉积的金刚石薄膜平均尺寸分别为0.77μm和0.75μm,薄膜内应力分别为-5.85GPa和-4.14GPa,TiC层的引入可以有效提高金刚石的形核密度和晶粒尺寸的均匀性,并减少薄膜残余应力;高温形核-低温生长的梯度降温法可以有效提高金刚石的形核密度和质量,并提高原始基体上沉积金刚石薄膜的附着性能。     

Superhydrophobic electrosprayed PTFE

This paper shows the deposition of superhydrophobic PTFE (polytetrafluoroethylene) films on FTO (fluorine doped tin oxide) coated glass slides, employing the electrospray technique, using a commercial PTFE particle suspension in water. Water contact angles as high as 167° were measured on the PTFE surface. Water drop sliding angles at 2° show a very low contact angle hysteresis. Scanning electron and atomic force microscopy images show the typical rough micro/nanostructure required for superhydrophobicity.     

Exploring the potential of high power impulse magnetron sputtering for growth of diamond-like carbon films

Amorphous carbon films are deposited employing high power impulse magnetron sputtering (HiPIMS) at pulsing frequencies of 250 Hz and 1 kHz. Films are also deposited by direct current magnetron sputtering (dcMS), for reference. In both HiPIMS and dcMS cases, unipolar pulsed negative bias voltages up to 150 V are applied to the substrate to tune the energy of the positively charged ions that bombard the growing film. Plasma analysis reveals that HiPIMS leads to generation of a larger number of ions with larger average energies, as compared to dcMS. At the same time, the plasma composition is not affected, with Ar⁺ ions being the dominant ionized species at all deposition conditions. Analysis of the film properties shows that HiPIMS allows for growth of amorphous carbon films with sp³ bond fraction up to 45% and density up to 2.2 g cm^− 3. The corresponding values achieved by dcMS are 30% and 2.05 g cm^− 3, respectively. The larger fraction of sp³ bonds and mass density found in films grown by HiPIMS are explained in light of the more intense ion irradiation provided by the HiPIMS discharge as compared to the dcMS one.     

Raman spectroscopy study of DLC films prepared by RF plasma and filtered cathodic arc

The build-up of intrinsic stress in carbon thin films deposited by vapour deposition can be a major cause of delamination. Arguably, this issue has been one of the main reasons why the industrial exploitation of carbon vapour deposited films has so far been of limited success. In the present study we deposited single and multilayer thin films of carbon and found that under certain deposition conditions, we were able to produce thin films free from delamination.Single and multilayer of films Diamond-like Carbon (DLC) were prepared by Plasma Immersion Ion Implantation and Deposition (PIIID) from two deposition systems: (1) Radio-Frequency (RF) plasma and (2) Filtered Cathodic Vacuum Arc (FCVA). Raman spectroscopy revealed a shift in the peaks previously identified as D and G band in the structures. The sp² and sp³ ratio contents were characterized by Raman spectroscopy.     

Deposition and structure characterization of carbon films prepared at atmospheric pressure by plasma jet

Amorphous carbon films were deposited on stainless steel substrates by plasma jet chemical vapor deposition (PJCVD). The carbon coatings have been prepared at atmospheric pressure in an argon/acetylene mixture. The Ar/C₂H₂ gas volume ratio varied from 100:1 to 200:1, while the distance between the plasma torch nozzle exit and the samples was 0.005–0.02 m. Scanning electron microscope analysis demonstrated that the surface roughness and growth rate of the coatings increase with the decrease of the Ar/C₂H₂ ratio. The ERDA results showed that the hydrogen concentration rises from 5 at.% to 27 at.% with the increase of the distance from 0.005 to 0.02 m. The increase of the Ar/C₂H₂ ratio from 100:1 to 200:1 slightly increases the hydrogen and oxygen concentration in the films. The Raman spectroscopy results indicated that the sp³ C–C carbon sites are replaced by sp³ CH_2–3 bonds with the increase of the deposition distance. The microhardness of the carbon films deposited at 0.005 m was in range of 7.1–9.3 GPa.     

Properties of nanostructured cubic boron nitride films prepared by the short-pulse laser plasma deposition techniques

Nanostructured cubic boron nitride (BN) films were synthesized on molybdenum substrates by using the short-pulse laser plasma deposition techniques. The surface morphologies, chemical compositions, bond structures, and mechanical properties of the obtained BN thin films have been investigated by scanning electron microscopy, Raman scattering, Fourier transform infrared spectroscopy (FTIR), energy dispersive spectra, and hardness measurements. High power density laser deposition yielded boron-rich BN nanorod arrays where tBN component dominates. Reducing power density down to 8 × 10⁷ W/cm² during laser plasma deposition produced flat cBN thin films. Typical TO and LO bands in the Raman and FTIR spectra of the cBN samples were identified. The cBN sample with hardness up to 40 GPa was obtained.