脉冲真空电弧离子镀在不锈钢上沉积类金刚石薄膜的研究

利用脉冲真空电弧离子镀技术在3Cr13不锈钢上制备了类金刚石(DLC)薄膜,通过Raman光谱分析了膜的结构特征,采用摩擦磨损试验机测试了薄膜在不同载荷下的摩擦系数,运用划痕仪研究了膜基的结合强度.结果表明:所镀制的薄膜具有典型类金刚石结构特征,膜中ID/IG为1.33;摩擦系数随着载荷的增大而减小,载荷为5 N,转速120 r/min时的摩擦系数为0.12;Ti过渡层的引入显著地提高了膜基结合力.     

Ellipsometric study of nanostructured carbon films deposited by pulsed laser deposition

When depositing carbon films by plasma processes the resulting structure and bonding nature strongly depends on the plasma energy and background gas pressure. To produce different energy plasma, glassy carbon targets were ablated by laser pulses of different excimer lasers: KrF (248 nm) and ArF (193 nm). To modify plume characteristics argon atmosphere was applied. The laser plume was directed onto Si substrates, where the films were grown. To evaluate ellipsometric measurements first a combination of the Tauc-Lorentz oscillator and the Sellmeier formula (TL/S) was applied. Effective Medium Approximation models were also used to investigate film properties. Applying argon pressures above 10 Pa the deposits became nanostructured as indicated by high resolution scanning electron microscopy. Above ~ 100 and ~ 20 Pa films could not be deposited by KrF and ArF laser, respectively. Our ellipsometric investigations showed, that with increasing pressure the maximal refractive index of both series decreased, while the optical band gap starts with a decrease, but shows a non monotonous course. Correlation between the size of the nanostructures, bonding structure, which was followed by Raman spectroscopy and optical properties were also investigated.     

脉冲电弧沉积类金刚石薄膜的厚度建模

从理论和实验出发,分析脉冲电弧源的放电机理,讨论了脉冲电弧源发散特性,得到影响膜厚空间分布的主要因素,建立膜厚空间分布和主要因素之间的数学模型,结果表明和实验数据吻合.     

过滤阴极真空电弧法制备四面体非晶碳薄膜

利用离面双弯曲过滤阴极其空电弧沉积系统，在Ф200mm单晶硅片上制备四面体非晶碳薄膜。利用Dectek3型表面轮廓仪检验膜厚均匀性(小于5％)，并利用扫描电子显微镜(SEM)、原子力显微镜(AFM)、激光拉曼光谱(Raman)、X射线光电子谱(XPS)以及纳米压痕(Nano—Indenter)仪器测试薄膜的性能和结构。结果表明：试验制备的薄膜是四面体非晶碳薄膜，其中sp^3键含量高达80％以上，薄膜表面纯净，几乎没有大颗粒的污染，表面粗糙度(Rq)小于0．3nm(取样面积1μm^2)，薄膜硬度可达50GPa，杨氏弹性模量高于550GPa。     

ITO thin films deposited by advanced pulsed laser deposition

Indium tin oxide thin films were deposited by computer assisted advanced PLD method in order to obtain transparent, conductive and homogeneous films on a large area. The films were deposited on glass substrates. We studied the influence of the temperature (room temperature (RT)-180 °C), pressure (1-6 × 10^− 2 Torr), laser fluence (1-4 J/cm²) and wavelength (266-355 nm) on the film properties. The deposition rate, roughness, film structure, optical transmission, electrical conductivity measurements were done. We deposited uniform ITO thin films (thickness 100-600 nm, roughness 5-10 nm) between RT and 180 °C on a large area (5 × 5 cm²). The films have electrical resistivity of 8 × 10^− 4 Ω cm at RT, 5 × 10^− 4 Ω cm at 180 °C and an optical transmission in the visible range, around 89%.     

Diagnostics of pulsed vacuum arc discharges by optical emission spectroscopy and electrostatic double-probe measurements

In this work the study of plasma characteristics by means of two of the most common techniques employed by the scientific community dedicated to the experimental plasma research is presented. The plasma was generated in a vacuum reaction chamber which was filled with hydrogen gas. Inside the chamber, two opposite electrodes were placed: the cathode, which was formed by a target of highly oriented pirolitic carbon and the anode. The electron temperature T_e and the electron density n_e were measured by using optical emission spectroscopy and electrostatic double probe, obtaining very close values for each case. T_e was calculated as approximately 0.7 eV and n_e of the order of 10¹³ cm⁻³. The optical emission measurement allows one to identify the substances that are in the plasma like C I, C II, C III, H I and H₂ and some possible reactions. The double-probe technique showed the plasma potential of about 24 V. The characteristic curve of the double probe exhibited oscillational plasma instabilities which could be attributed to the charge density variation or other factors, such as the employed AC signal and the geometric probe.     

Influence substrate temperature on structural properties of TiN/TiC bilayers produced by pulsed arc techniques

This paper presents an investigation regarding influence of substrate temperature during deposition on the characteristics of TiN/TiC bilayers grown by plasma-assisted pulsed arc discharge. The substrate temperatures were 50, 100 and 150 °C. The gases used in the experiment were N₂ for TiN and CH₄ for TiC. These coatings were studied by X-ray diffraction techniques determining the variation of the lattice parameters for each film. The Scherrer equation was used to calculate the crystallite size and the micro-strain. The X-rays analysis showed an increase in the substrate temperature made the formation of TiC in (2 0 0) orientation favorable. The sample grown at 50 °C presented low crystallinity and it was increased as the substrate temperature increases. Using a scanning probe microscopy, with atomic force microscopy, phase detection microscopy and force modulation microscopy modes, the morphology of the deposited layer was studied and macro-particles were observed using gray scales to identify differences in the friction coefficient and material composition in the coatings. It has been found that the increment of the substrate temperature decreases the condensation of microdroplets on the surface. Lateral force microscopy was used to calculate friction coefficient of the TiN and TiC monolayers and we found that the friction coefficient is smaller for TiC than for TiN.     

Transparent conducting ZnO thin films deposited by vacuum arc plasma evaporation

A high rate deposition of co-doped ZnO:Ga,F and ZnO-In₂O₃ multicomponent oxide thin films on large area substrates has been attained by a vacuum arc plasma evaporation method using oxide fragments as a low-cost source material. Highly transparent and conductive ZnO:Ga,F and ZnO-In₂O₃ thin films were prepared on low temperature substrates at a deposition rate of approximately 375 nm/min with a cathode plasma power of 10 kW. A resistivity of 4.5×10⁻⁴ Ω cm was obtained in ZnO:Ga,F films deposited at 100 °C using ZnO fragments co-doped with 1 wt.% ZnF₂ and 1 wt.% Ga₂O₃ as the source material. In addition, the stability in acid solution of ZnO films was improved by co-doping. It was found that the Zn/(In+Zn) atomic ratio in the deposited ZnO-In₂O₃ thin films was approximately the same as that in the fragments used. The ZnO-In₂O₃ thin films with a Zn/(In+Zn) atomic ratio of approximately 10-30 at.% deposited on substrates at 100 °C exhibited an amorphous and smooth surface as well as a low resistivity of 3-4×10⁻⁴ Ω cm.     

脉冲真空放电离子密度的测量

由于采用脉冲放电沉积技术能够克服连续电弧离子镀沉积时产生的液滴及负偏压放电的缺点，特别是它在镀制类金刚石薄膜中显示出来的独特性能：不含氢和硬度高，使其在薄膜沉积技术中越来越受到广大研究者的重视。为了更深入地研究薄膜的沉积工艺和薄膜性能之间的关系，迫切需要对脉冲真空放电等离子体的微观参数进行深入透彻的研究，如离子密度及其空间分布等。本文介绍了测量脉冲真空电弧离子源离子密度的方法，并采用该方法测量了脉冲真空电弧离子源离子密度及其空间分布，分析和研究了影响离子空间分布的各种参数。     

Characterization of pulsed laser deposited hydrogenated amorphous silicon films by spectroscopic ellipsometry

The wide absorption band of hydrogenated amorphous silicon (a-Si:H) is being realized as a key component of solar cells on glass. In this study, a-Si:H films were prepared by reactive pulsed laser deposition onto silicon and glass substrates. Ellipsometry showed that the optical properties of the films are effectively independent on the choice of substrate. According to the optical properties, the character of the films changes from amorphous silicon to dielectric as the hydrogen background pressure increases from 0 to 25 Pa. This observation was attributed to oxygen incorporation indicated by Rutherford Backscattering Spectrometry. Furthermore, a refractive index gradient in depth was revealed, which was attributed to the oxygen concentration gradient.     

脉冲电弧放电电离甲醇/氨水溶液合成结晶氮化碳薄膜

利用脉冲电弧放电在大气压下产生的高密度等离子体研究了结晶氮化碳薄膜的低温合成。直流脉冲电弧等离子体由甲醇／氨水溶液液滴通过高压电极时诱导放电产生。利用扫描电子显微镜、X射线衍射、Raman光谱分析了薄膜样品的形貌和结构。在基片温度为450℃时所制样品的X射线衍射分析表明薄膜中含有α-C3N4和β-C3N4两种结构晶体，Raman光谱给出了明显的特征峰，这些特征峰与氮化碳晶体的理论预言值符合较好。当基片温度提高到550℃时．Raman光谱分析表明，样品为炭膜。     

介质阻挡放电化学气相沉积法制备DLC薄膜研究

采用介质阻挡化学气相沉积法(DBD CVD)在Si及石英衬底上、室温下成功的沉积出光滑、致密、均匀、膜基结合较好的类金刚石(DLC)薄膜,并考察了电源电压对类金刚石薄膜结构及性能的影响。拉曼光谱(Raman)、扫描电子显微镜(SEM)、原子力显微镜(AFM)、紫外可见光谱(UV Vis)、高阻仪等测试及分析结果显示DBD CVD 法适于制备高质量硬质DLC薄膜。对DBD放电做了理论分析,结果与工艺研究的结论相符合。     

Investigation of alumina-silica films deposited by pulsed injection metal-organic chemical vapour deposition

This work is devoted to deposition of alumina-silica films using an innovative pulsed injection metal organic chemical vapour deposition technique and aluminium tri(iso-propoxide) (Al(i-OPr)₃) and tetraethoxysilane (TEOS) as precursors. The deposited aluminium silicate films have been characterised by scanning electron microscopy, infrared spectroscopy, X-ray diffractometry and capacitance-voltage (C-V) measurements. The investigation of the deposition at different Si/Al ratios and substrate temperatures has shown that the growth rate increases with the increase of Al(i-OPr)₃ proportion in solution and decreases as the proportion of TEOS increases. We have also shown that aluminium content in the film increases at lower deposition temperatures while silicon content increases at higher temperatures. The permittivity of the films determined from C-V measurements decreases with increasing substrate temperature. It was found that films deposited at substrate temperatures of 600 or 700 °C and with the highest Si/Al ratio have the lowest dielectric permittivity. This research should be useful for further development of MOCVD technology for the deposition of aluminosilicate-based dielectric materials with controlled dielectric permittivity.     

Evaluation of microstructures and mechanical properties of diamond like carbon films deposited by filtered cathodic arc plasma

Diamond-like carbon (DLC) films were deposited by a cathodic arc plasma evaporation (CAPD) process, using a mechanical shield filter combined with a magnetic filter with enhanced arc structure at substrate-bias voltage ranging from − 50 to − 300 V. The film characteristics were investigated using Raman spectroscopy, X-ray photoelectron spectroscopy (XPS), atomic force microscopy (AFM) and high-resolution transmission electron microscopy (HRTEM). The mechanical properties were investigated by using a nanoindentation tester, scratch test and ball on disc wear test. The Raman spectra of the films showed that the wavenumber ranging from 900 to 1800 cm^− 1 could be deconvoluted into 1140 cm^− 1, D band and G band. The bias caused a significant effect on the sp³ content which was increased with the decreasing of I_D/I_G ratio. The XPS spectra data of the films which were etched by H⁺ plasma indicated the sp³ content are higher than those of the as-deposited DLC films. This implied that there is a sp²-rich layer present on the surface of the as-deposited DLC films. The nanoindentation hardness increased as the maximum load increased. A 380 nm thick and well adhered DLC film was successfully deposited on WC-Co substrate above a Ti interlayer. The adhesion critical load of the DLC films was about 33 N. The results of the wear tests demonstrated that the friction coefficient of the DLC films was between 0.12 and 0.2.     

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.     

工艺参数对阴极电弧离子镀ZrN薄膜表面形貌及结构的影响

本文采用阴极电弧离子镀技术制备了ZrN膜层,研究了工作气压、偏压、弧流等工艺参数对ZrN膜层表面形貌和结构的影响,分别用扫描电镜(SEM)、X射线衍射仪(XRD)分析了膜层的表面形貌及相结构。结果表明:工作气压、偏压、弧电流等工艺参数对ZrN膜层的表面形貌有较大的影响,在本实验内适当提高N2压强、偏压以及在稳弧前提下降低弧流有利于减少大颗粒,改善ZrN膜层表面形貌,提高膜层综合性能;不同工艺参数下制备的ZrN膜层均具有典型的面心立方结构,工作气压和弧电流对ZrN膜层晶体生长方向的影响较小,偏压对晶体生长方向的影响显著,在20 V偏压下,晶体呈(200)面择优取向,继续提高偏压(100 V~300 V),晶体生长呈(111)面择优取向。     

Production of porous carbon thin films by pulsed laser deposition

Pulsed laser deposition (PLD) has been used together with the Glancing Angle Deposition (GLAD) technique [1 and 2] for the first time to produce highly porous structured films. A laser produced carbon plasma and vapour plume was deposited at a highly oblique incident angle onto rotating Si substrates, resulting in films exhibiting high bulk porosity and controlled columnar microstructure. By varying the substrate rotation rate, the shape of the microcolumns can be tailored. These results extend the versatility of the GLAD process to materials not readily deposited by means of traditional physical vapour deposition techniques.     

Transparent p-type conducting K-doped NiO films deposited by pulsed plasma deposition

Transparent p-type conducting K-doped NiO thin films were prepared by pulsed plasma deposition. The structural, electrical and optical properties of the films were investigated using X-ray diffraction, atomic force microscope, X-ray photoelectron spectroscopy, Hall measurement, and ultraviolet-visible spectroscopy, respectively. The dependency of film properties on K doping content and substrate temperature was studied. The film with K doping content of 25 at.% deposited at room temperature exhibits the highest conductivity of 4.25 S cm^− 1 and an average transmittance of nearly 60% in visible light region.     

Time and space resolved Langmuir probe measurements of a pulsed vacuum arc plasma

The time and space evolution of pulsed vacuum arc plasma parameters have been measured using a single cylindrical Langmuir probe in a free expansion cup. Electron density n_e, effective electron temperature T_eff and electron energy distribution function (EEDF) are derived from the I-V curves using Druyvesteyn method. Results show that during the discharge time, the electron density n_e is between 0.27 and 1.82 × 10¹⁸ m⁻³ and the effective electron temperature T_eff is between 6.14 and 14.72 eV, both of which decrease as a function of the discharge time. The electron energy distribution function (EEDF) is no-Maxwellian since the high-energy electrons depart from the Maxwellian distribution. Due to the plasma expansion, the electron density n_e decreases as increase of the expansion distance, but the effective electron temperature T_eff is weakly dependent on the distance in the free expansion cup.