Transport of evaporated material through support gas in conjunction with ion plating: I

This paper deals with theoretical and experimental investigations of the thickness distribution of thin films deposited by evaporation under an inert support gas at various pressures. This approach is considered as a first step to describe the material transport in ion plating. In the first part a quantitative treatment based on numerical solutions of the Laplace equation is presented. The solutions are used to calculate the thickness distribution on plane and cylindrical substrate configurations. A comparison of the results with experimental data obtained for silver deposition in argon at pressures of 1.33–6.6 Pa reveals good agreement between measured and calculated thickness distributions of the films. For lower pressures, however, the diffusion model is no longer realistic, and it should be replaced by Monte Carlo calculations of the particle movement. This will be the topic of the second part.     

Coating material innovation in conjunction with optimized deposition technologies

Concentrating on physical vapour deposition methods several examples of recently developed coating materials for optical applications were studied for film deposition with optimized coating technologies: mixed evaporation materials for ion assisted deposition with modern plasma ion sources, planar metal and oxide sputter targets for Direct Current (DC) and Mid-Frequency (MF) pulsed sputter deposition and planar and rotatable sputter targets of transparent conductive oxides (TCO) for large-area sputter deposition.Films from specially designed titania based mixed evaporation materials deposited with new plasma ion sources and possible operation with pure oxygen showed extended ranges of the ratio between refractive index and structural film stress, hence there is an increased potential for the reduction of the total coating stress in High-Low alternating stacks and for coating plastics.DC and MF-pulsed sputtering of niobium metal and suboxide targets for optical coatings yielded essential benefits of the suboxide targets in a range of practical coating conditions (for absent in-situ post-oxidation ability): higher refractive index and deposition rate, better reproducibility and easier process control, and the potential for co-deposition of several targets.Technological progress in the manufacture of rotatable indium tin oxide (ITO) targets with regard to higher wall-thickness and density was shown to be reflected in higher material stock and coater up-time, economical deposition rates and stable process behaviour. Both for the rotatable ITO targets and higher-dense aluminum-doped zinc oxide (AZO) planar targets values of film transmittance and resistivity were in the range of the best values industrially achieved for films from the respective planar targets. The results for the rotatable ITO and planar AZO targets point to equally optimized process and film properties for the optimized rotatable AZO targets currently in testing.     

Texture and columnar structure of evaporated cobalt films: II

The dependence of the columnar structure on the degree of texture was investigated in cobalt films prepared at various evaporation rates. The angle of incidence was 70° and the substrate temperature 200°C. The evaporation rates range from 70 to 11 000 Å min^-1. The texture was analysed by means of pole figures and the columnar structure was observed by replica electron microscopy. The results obtained are as follows. (1) With an increase of the degree of texture the gaps between columnar grains increase but the angle of inclination of the columnar grains decreases. (2) In the film with a high degree of texture bundles of columnar grains exist. On the basis of these results, the correlation between the texture and the columnar structure is briefly discussed.     

探讨电弧离子镀中“大颗粒”净化方法

传统电弧离子镀存在着大颗粒污染、沉积温度相对较高和易引发微弧击穿效应等诸多不足,制约其在精细薄膜、低温沉积和功能薄膜等方面的应用。本文简要介绍了电弧离子镀中大颗粒的形成机理,旨在探讨用磁场控制、脉冲电弧、磁过滤及脉冲偏压等方法来减少大微粒污染及其作用机理。     

A study of evaporated gold-tin films using transmission electron microscopy: II

Using transmission electron microscopy the time development at room temperature of the different Au-Sn phases present in evaporated gold-tin films was studied. An interaction was found to take place which resulted in the formation of AuSn and AuSn₄ at early stages and a subsequent transformation into other Au-Sn phases depending on the overall composition.     

Effects of process parameters on the ionization in triode ion plating

One effective way of enhancing ionization in ion plating is to use a negatively biased hot filament. Such triode ion-plating systems are currently used in industry to deposit wear-resistant thin film coatings on cutting tools, for example. In this work the effect of a negatively biased hot electron-emitting filament on ionization efficiency is studied. The effects of the process parameters are studied by varying the argon and nitrogen pressure in the deposition chamber. The ionization efficiency is calculated and shown to depend on the process parameters. The effects of the size of the process chamber have been investigated experimentally by carrying out experiments with laboratory and production units of different sizes.     

Simulation of material sputtering with a focused ion beam

The evolution of the surface of a sample under the action of a focused ion beam (FIB) has been simulated using the level set method in the framework of a model that takes into account the redeposition of atoms primarily sputtered by the incident ions. In order to improve quantitative agreement between the results of simulation and experimental data, special experiments have been performed so as to refine the FIB shape and the model of secondary sputtering of the redeposited material. Using the example of rectangular cavities, it is shown that the proposed approach ensures high-precision simulation of a surface relief formed under the effect of an FIB.

     

非晶金刚石离子镀膜机自动化控制系统的设计

结合非晶金刚石离子镀膜机的工艺特点和要求，本文介绍了一种成功应用的分布式控制系统的设计，重点讨论了控制系统的硬件配置、软件设计、通信服务程序以及软件编程中的几个控制算法。     

Dynamics of a gas bubble rising through a thin immersed layer of granular material: an experimental study

 Packings of non-cohesive grains, immersed in a fluid, differ significantly from classical porous media as the grains, subjected to stresses and flows, can move within the sample, changing then the local properties of the material. We study experimentally the conditions for a gas to pass through a layer of immersed granular material. Above a threshold pressure, which depends mainly on the grains size and on the surface free energy of the liquid-gas interface, the gas creates a channel within the whole thickness of the layer. Received: 23 January 2002     

The influence of the electronic current on the measurement of ion polarization in evaporated silicon oxide

In this paper the influence of the electronic leakage current on the measurement of the ion polarization mechanism in thin film capacitors is investigated. A simple theory is given and is applied to small signal and large signal cases. The theoretical results are compared with the experimental data. In order to fit the theoretical analysis to the experimental results, a new hypothesis concerning ion enhancement is introduced.     

TOF-SIMS with argon gas cluster ion beams: a comparison with C60+

Time-of-flight secondary ion mass spectrometry (TOF-SIMS) is an established technique for the characterization of solid sample surfaces. The introduction of polyatomic ion beams, such as C(60), has provided the associated ability to perform molecular depth-profiling and 3D molecular imaging. However, not all samples perform equally under C(60) bombardment, and it is probably nai?ve to think that there will be an ion beam that will be applicable in all situations. It is therefore important to explore the potential of other candidates. A systematic study of the suitability of argon gas cluster ion beams (Ar-GCIBs) of general composition Ar(n)(+), where n = 60-3000, as primary particles in TOF-SIMS analysis has been performed. We have assessed the potential of the Ar-GCIBs for molecular depth-profiling in terms of damage accumulation and sputter rate and also as analysis beams where spectral quality and secondary ion yields are considered. We present results with direct comparison with C(60) ions on the same sample in the same instrument on polymer, polymer additive, and biomolecular samples, including lipids and small peptides. Large argon clusters show reduced damage accumulation compared with C(60) with an approximately constant sputter rate as a function of Ar cluster size. Further, on some samples, large argon clusters produce changes in the mass spectra indicative of a more gentle ejection mechanism. However, there also appears to be a reduction in the ionization of secondary species as the size of the Ar cluster increases.     

Transport properties of lithium in the gas phase

The collision cross section of lithium atoms is determined by generalizing empirical data on the and of Na, K, Rb, and Cs vapors and quantum calculations of the potential curves of Li₂. The ₁ and ₁ of Li vapors are calculated.Translated from Inzhenerno-Fizicheskii Zhurnal, Vol. 39, No. 6, pp. 993–998, December, 1980.     

真空离子镀铬合金厚膜替代电镀硬铬工艺研究(一)

离子镀功能厚镀膜主要用于提高工件耐磨性和耐蚀性,膜层厚度40μm以上。离子镀铬合金厚镀膜代替电镀硬铬工艺研发,已取得满意成果,可以投入工业生产,可以向社会提供技术及专用设备。     

支持向量机在混合气体种类光谱识别中的应用

针对混合气体种类光谱识别中组分气体特征谱线重叠严重的问题,将支持向量机用于混合气体种类光谱识别中,提出了一种基于支持向量机二值分类识别模型的逐一混合气体种类识别方法。利用支持向量机的核函数变换,将特征谱线重叠严重的光谱在高维空间变换为线性可分后再逐一进行混合气体种类识别。在天然气气体种类识别实验中,比较了不同核函数、数据预处理、特征提取、训练样本数等条件与识别结果的关系,结果表明,方法对1%浓度以上的天然气组成气体的正确识别率大于97%,在理论和实际应用中具有重要的推广价值。     

Quantitative and time-resolved detection of lithium plating on graphite anodes in lithium ion batteries

The ability of fast and safe charging is critical for the further success of lithium ion batteries in automotive applications. In state-of-the-art lithium ion batteries, the charging rate is limited by the onset of lithium plating on the graphite anode. Despite its high importance, so far no analytical technique has been available for directly measuring lithium plating during battery charge. Herein, we introduce operando electron paramagnetic resonance (EPR) spectroscopy as the first technique capable of time-resolved and quantitative detection of lithium metal plating in lithium ion batteries. In an exemplary study, the C-rate dependence of lithium metal plating during low-temperature charging at ?20?°C is investigated. It is possible to quantify the amount of ‘dead lithium’ and observe the chemical reintercalation of plated lithium metal. In this way, it is possible to deconvolute the coulombic inefficiency of the lithium plating/stripping process and quantify the contributions of both dead lithium and active lithium loss due to solid electrolyte interphase (SEI) formation. The time-resolved and quantitative information accessible with operando EPR spectroscopy will be very useful for the optimization of fast charging procedures, testing of electrolyte additives, and model validation.     

脉冲偏压下电弧离子镀等离子体负载的等效电路模型及其定量表征

为了解决电弧离子镀(AIP)工艺中脉冲偏压电源与AIP等离子体负载间的匹配问题,结合脉冲偏压下AIP工艺实验,运用等离子体鞘层理论、电路理论和仿真模拟技术,得到AIP等离子体负载本质上是由鞘层引起的容性负载,在电路中可以等效为电容和电阻相并联的单元;根据AIP等离子体鞘层演化的特性,将AIP等离子体负载的等效电容表征为与时间无关而只与脉冲偏压幅度和等离子体相关参数有关的量,AIP等离子体负载的等效电阻,可以在直流偏压下通过测量与脉冲偏压幅值对应的AIP等离子体负载电流来确定.经验证,本文建立的AIP等离子体负载的等效电路模型及其定量表征是有效性的.