磁场非平衡度对CrN_x镀层性能的影响

使用具有不同非平衡度的磁控管直流磁控溅射技术沉积CrN_x镀层,并用Langmuir探针诊断、高斯仪测量、Ansys软件模拟等手段进行表征,研究了磁场非平衡度对溅射等离子体的空间分布状态以及CrN_x镀层的微观结构、硬度及摩擦性能的影响。结果表明:低非平衡度磁控管（K为2.78）将多数离子束缚在靶材表面大约6 cm范围内,而对于高非平衡度磁控管（K为6.41）则在此区域没有类似的高密度等离子体存在。随着磁场非平衡度的增大,CrN_x镀层的厚度递增,物相结构也从Cr+Cr₂N依次向Cr+Cr₂N+CrN和Cr₂N+CrN转化,且镀层的平整度和致密性随之明显改善。同时,CrN_x镀层的硬度随着非平衡度的增大而提高,摩擦系数则随之减小。     

磁控溅射靶材刻蚀特性的模拟研究

靶材刻蚀特性是研究磁控溅射靶材利用率、薄膜生长速度和薄膜质量的关键因素.本文用有限元 分析软件ANSYS模拟了磁控溅射放电空间的磁场分布,用粒子模拟软件OOPIC Pro(object oriented particle in cell)模拟了放电过程,最后用SRIM(stopping and range of ions in matter)模拟了靶材的溅射特性,得到了靶材的刻蚀形貌和刻蚀速度,并讨论了不同工作气压和不同阴极电压对靶材刻蚀的影响.模拟结果表明:靶材刻蚀形貌与磁场分布有关,磁通密度越强,对应的靶材位置刻蚀越深;靶材的刻蚀速度随阴极电压的增大而增大,而当工作气压增大时,靶材的刻蚀速度先增大后趋向平衡,当工作气压超过一定的值时,刻蚀速度随气压的增大开始减小.模拟结果与实验观测进行了比较,二者符合较好.     

第十九讲 真空溅射镀膜

正(接2016年第6期第80页)图70给出了在非平衡四靶闭合磁场结构和四靶镜像磁场结构中,磁控溅射系统的磁场分布情况。比较这两种结构的磁场分布情况,可以看出两者在靶面附近的磁场差别不大,在内外磁极之间以横向磁场为主,通过对电子的紧约束,形成一个电离度很高的等离子体阴极区。区内的正离子对靶面的强烈溅射刻蚀构成了靶材中性粒     

第十九讲 真空溅射镀膜

正(接2014年第3期第80页)5溅射产额与工作气体压力的关系在较低工作气体压力时,溅射产额不随压力变化,在较高工作气体压力时,溅射产额随压力增大而减少,见图12。这是因为工作气体压力高时,溅射粒子与气体分子碰撞而返回阴极(靶)表面所致。6溅射产额与温度的关系图13是用45 keV的Xe+对几种靶材进行轰击时,其溅射产额(由靶材失重间接表达)与靶材     

第十九讲 真空溅射镀膜

<正>(接2016年第5期第82页)普通磁控溅射靶的磁场集中在靶面附近(见图64a),靶的磁场将等离子体紧密地约束在靶面附近,而基片附近的等离子体很弱,基片不会受到离子和电子较强的轰击。而非平衡磁控溅射阴极的磁场大量向靶外发散(见图64b),非平衡磁控溅射阴极的磁场可将等离子体扩展到远离靶面处,使基片浸没其中。通过改变磁控靶中磁体的配置方式,有意识地增强或削弱其中一个磁极     

钼板轧制及热处理工艺对溅射薄膜微观组织及性能的影响

通过研究钼金属靶材轧制变形量及热处理工艺对溅射薄膜的微观组织、表面粗糙度及晶形的影响,结果表明:变形量为80%的钼靶材溅射制备的薄膜晶化程度优于变形量小的靶材溅射薄膜;溅射相同的薄膜厚度,随着靶材变形量的增大,溅射薄膜的方阻越大;1373K退火靶材溅射薄膜的粗糙度最小,表面颗粒最细小均匀,晶粒取向明显。     

旋转圆柱磁控溅射阴极设计和磁场强度分析计算

磁场分布对旋转圆柱靶磁控溅射阴极的性能起着决定性作用。本文应用ANSYS有限元方法对单个旋转圆柱靶和孪生旋转圆柱靶阴极磁场强度进行了模拟计算,得到的磁场分量Bx、By在靶材表面的二维磁场分布,并利用Bx、By计算得到了圆柱靶表面切线方向的磁场强度Bτ。通过调节磁铁的高度、宽度、磁铁间夹角以及孪生靶间距和靶中心轴旋转角度等参数对磁场分布进行了优化,优化后的圆柱磁控溅射阴极的表面切线方向磁场强度增加了大约40%,所对应的溅射区磁场面积也增大了大约45%。     

电磁阴极磁场分布对磁控溅射系统伏安特性的影响

本文设计了一种新型圆形平面阴极磁控溅射源.该源具有独特的三极线圈结构,改变各线圈励磁电流可调节靶面磁场强度的大小和分布.通过对系统气体放电伏安特性随各线圈励磁电流大小变化规律的分析,以及对距靶面60mm基片台处等离子体束流密度大小和分布的测试,探讨了阴极磁场分布对磁控溅射系统伏安特性的影响.实验结果表明阴极磁场分布模式对气体放电稳定性和等离子体分布影响显著,当阴极磁场呈现收敛型分布时,二次电子被紧密束缚在靶面附近,降低了基片台附近等离子体束流密度,却增大等离子体束流径向分布均匀性.调节非平衡线圈励磁电流,在附加磁场的作用下,阴极磁场呈现发散型分布,二次电子被引向基片台附近,使得基片台附近等离子体束流密度显著增加但径向均匀性变差.     

溅射沉积技术的发展及其现状

论述了溅射沉积薄膜技术的发展历程及其目前的研究应用状况.二极溅射应用于薄膜制备,揭开了溅射沉积技术的序幕,磁控溅射促使溅射沉积技术进入实质的工业化应用,并通过控制磁控靶磁场的分布方式和增加磁控靶数量,进一步发展为非平衡磁控溅射、多靶闭合式非平衡磁控溅射等,拓宽了应用范围.射频、脉冲电源尤其是脉冲电源在溅射技术中的使用极大地延伸了溅射沉积技术的应用范围.     

射频磁控反应溅射制备Al2O3薄膜的工艺研究

采用射频磁控反应溅射法,以高纯Al为靶材,高纯O2为反应气体,在不锈钢和单晶Si基片上成功地制备了氧化铝(Al2O3)薄膜,并对氧化铝薄膜的沉积速率、结构和表面形貌进行了研究.结果表明,沉积速率随着射频功率的增大先几乎呈线性增大而后缓慢增大;随着溅射气压的增加,沉积速率先增大,在一定气压时达到峰值后继续随气压增大而减小,同时随着靶基距的增大而减小;随着氧气流量的不断增加,靶面溅射的物质从金属态过渡到氧化物态,沉积速率也随之不断降低.X射线衍射图谱表明薄膜结构为非晶态;用原子力显微镜对薄膜表面形貌观察,薄膜微结构为柱状.     

溅射沉积氢化非晶硅中辉光放电等离子体的Langmuir探针诊断

为揭示磁控溅射辉光放电等离子体参量对Si薄膜沉积过程的本质影响,采用Langmuir探针于不同的靶电流、靶基距和氢分压条件下对直流辉光放电等离子体进行了诊断,分析了直流辉光放电等离子体参量(离子密度、离子流通量、等离子体电势、电子密度、电子温度)的变化规律,并以此为依据探讨了其对Si靶溅射过程和溅射Si粒子输运过程的影...     

Variations of microstructure, conductivity and transparency of Al-doped ZnO thin films prepared by radio frequency magnetron sputtering with target-substrate distances

Al-doped ZnO films were deposited at different target-substrate distances by radio frequency magnetron sputtering. The crystallite size of the films is reduced with increasing the target-substrate distance, but the (002) preferential orientation of ZnO is observed for all the films. It is found that the target-substrate distance has a great influence on the carrier concentration in the films. Reduction of the target-substrate distance is favorable to obtain higher carrier concentrations. The lowest resistivity of 1.1 × 10⁻³ Ω cm is obtained for the film at target-substrate distance of 55 mm. The optical transmittance in the visible range remains higher than 90% for all the films, and the absorption edge shifts towards the shorter wavelength side with decreasing the target-substrate distance. The band gap was widened by 0.11 eV due to the Burstein-Moss (BM) shift from 3.33 eV to 3.44 eV with the reduction of the target-substrate distance from 60 mm to 55 mm.     

超高速碰撞产生瞬态磁场的时间尺度特征

在超高速碰撞的早期阶段会产生瞬态等离子体云,等离子体云能以某种机理产生电流和磁场。在靶板表面的等离子体云中产生的非线性电子温度和电子密度梯度将产生磁场,场的持续时间从10-6s到约60s,依赖于弹丸的碰撞能量。本文利用超高速碰撞产生等离子体诱生磁场的一维理论模型,理论推导了喷出物诱生磁场的峰值,得到了碰撞喷出物膨胀过程中磁场增强、磁场衰减的时间尺度特征及磁感应强度峰值。结合超高速正碰撞实验,给出了碰撞喷出物膨胀等离子体云中瞬态磁场的时间尺度,并与理论时间尺度进行了比较,结果基本一致。     

磁控溅射膜厚均匀性与靶-基距关系的研究

从理论上分析了平面磁控溅射靶沉积薄膜的厚度均匀性.根据磁控溅射阴极靶刻蚀的实际测量数据,建立了靶的刻蚀速率方程,以此为依据,对膜厚均匀性的有关公式进行了讨论.采用计算机计算了基片处于不同靶-基距时,膜厚均匀性的分布.研究结果表明,随着靶基距的增加,膜厚均匀性逐渐变好.在同样的靶基距下,沿靶长度方向的均匀性明显优于宽度方向.最后,通过实验证实了上述结论.     

Fluctuations of the magnetically-supported dc discharge in coaxial configuration

Floating potential fluctuations have been studied in DC discharge plasma in two cylindrical magnetron systems using the data from single and double cylindrical Langmuir probes. The power spectral density was calculated from the experimental data in the range of magnetic fields 15-35 mT and at different pressures and probe axial positions within the discharge vessel. Plots of power spectral density vs frequency and vs wave number are presented. The possible mechanism of generation of observed fluctuations in relation to their measured properties is discussed.     

Ionization kinetics in a supersonic xenon plasma flow entering electric field

We have studied xenon plasma moving in a supersonic diffuser in external electric and magnetic fields. The main physical parameters of the plasma (electron temperature and density) were determined using specially developed methods based on the theory of continuous optical emission from inert gas atoms. These experimental data are compared to the results of theoretical calculations. Based on an analysis of the results of spectroscopic measurements, a mechanism of plasma ionization is established which is capable of maintaining a high degree of ionization in the supersonic xenon plasma flow.     

Effect of Iron Particles Size on the High-Frequency Magnetic Properties of Iron-Borosilicate Soft Magnetic Composites

Iron-borosilicate magnetic composites could be applied as a soft magnetic material in high temperature and high frequency applications. In this research, the magnetic properties of soft magnetic composites with different iron particle sizes made by spark plasma sintering have been investigated. Different magnetic properties such as permeability, loss factor, and quality factor were examined up to frequencies in the order of kilohertz. The microstructural observations indicated the distribution of borosilicate on the iron grain boundaries. The results revealed that the loss factor is smaller for composites with fine particles at high frequencies. In addition, the magnetic impedance for smaller particles was greater. It was also found that the permeability and quality factor of composites with coarse particles are larger than those of fine particles. Indeed, when the particles become coarse, the density of porosities and consequently, the demagnetizing fields decrease which result in the increase of permeability. Furthermore, when the size of particles reduces, the density of grain boundaries enhances which is the main reason of lower loss factor achieved in the composites with fine particles.     

Diffusion layer growth at Zn/Cu interface under uniform and gradient high magnetic fields

As a common phenomenon occurring in many material processes, diffusion may induce significant changes in composition and microstructure near the interface. In the present study, liquid/solid (Zn/Cu) interface diffusion experiments in high magnetic fields (up to 12 T) were conducted and the thickness changes of diffusion layer under different magnetic field conditions were examined. It was found that there were no noticeable effects of high magnetic fields on the formation of intermetallic phases at the interface. However, the magnetic flux density exerted a non-linear influence on the diffusion layer thickness. This phenomenon should be attributed to the effect of magnetic fields suppressing natural convection and inducing thermo-electromagnetic convection. In addition, the diffusion of Zn into Cu could be retarded by a magnetic field gradient. These results indicate that both the strength and the gradient of high magnetic fields can be used to control the diffusion behavior.     

Low-frequency transient electric and magnetic fields coupling to child body

Much of the research related to residential electric and magnetic field exposure focuses on cancer risk for children. But until now only little knowledge about coupling of external transient electric and magnetic fields with the child's body at low frequency transients existed. In this study, current densities, in the frequency range from 50 Hz up to 100 kHz, induced by external electric and magnetic fields to child and adult human body, were investigated, as in residential areas, electric and magnetic fields become denser in this frequency band. For the calculations of induced fields and current density, the ellipsoidal body models are used. Current density induced by the external magnetic field (1 microT) and external electric field (1 V/m) is estimated. The results of this study show that the transient electric and magnetic fields would induce higher current density in the child body than power frequency fields with similar field strength.     

利用强磁场控制过共晶铝硅合金的凝固组织

研究了静磁场和梯度磁场的强度和方向对Al-15.7%Si合金宏观和微观凝固组织的影响.结果表明,在不同的磁场条件下,从过共晶合金中析出的初晶硅粒的分布状况和共晶硅的形态和密度有显著不同.通过改变磁感应强度和磁场梯度的大小和方向可有效控制初晶硅的分布;合理控制强磁场的操作参数可达到细化铝硅共晶体的目的.强磁场的磁化力和洛伦兹力通过控制初晶硅颗粒迁移行为来改变其在合金基体中的分布状态,通过影响凝固过程中的对流现象改变合金的凝固组织.