外加磁场对磁控溅射靶利用率的影响

通过在基片上直接放置一块永久磁铁来研究外加磁场对磁控溅射靶利用率的影响。实验发现，外加磁场的引入改变了靶表面附近的磁场分布，因而靶的刻蚀环的位置、宽度和深度均发生了明显的变化，靶的利用率在S—S构型和S—N构型中均比无外加磁场时要高。利用空间模拟磁场成功的解释这一实验现象。在S—S构型和S—N构型中，后靶的刻蚀深度轮廓线比较平坦，相对刻蚀深度值更大，更能有效地提高靶的利用率。     

采用导磁片改造磁控装置提高靶材利用率

通过对真空溅镀生产线靶材的刻蚀情况观测,发现所有产线均存在不同程度的靶面刻蚀不均现象,而3号线尤为突出,其端部刻蚀深度相对于其它部位刻蚀深度较深,导致靶材使用寿命短,利用率低.采用高磁导率材料电工纯铁DT4制作导磁片装入磁控装置,试验结果表明,降低了靶面刻蚀不均匀度,靶材利用率提高至少10％.     

磁控溅射矩形靶磁场的优化设计

磁控溅射靶材的利用率在降低生产成本中起着重要作用.正交的靶电磁场能显著地延长电子的运动路程,增加同工作气体分子的碰撞几率,提高等离子体密度,使磁控溅射速率数量级的提高,因此靶面正交电磁场的分布将决定靶的烧蚀情况.提出了2种改善矩形平面靶磁场分布的方法,经过分析,这2种设计将拓宽靶面的刻蚀范围,提高靶材的利用率.     

磁控溅射设备中铜靶刻蚀形貌的仿真计算研究

提出了一种铜靶刻蚀形貌模拟方法,基于靶材溅射率与靶材表面磁场水平分量成正比的假设,以美国应用材料公司的小行星PVD磁控溅射装置为算例,实现了复杂运动轨迹铜靶刻蚀形貌的模拟,仿真计算结果与实际设备中铜靶刻蚀形貌有较好的一致性,为通过磁场分布研究靶材刻蚀形貌提供了一种理论方法。     

直流磁控溅射中矩形平面靶刻蚀形貌的数值计算及优化

对普通矩形平面靶的磁场分布、电子运动轨迹和电子分布进行了理论计算。通过磁场的解析表达式,解出电子在磁场中的运动方程,求得并从理论上解释了电子的运动轨迹。由电子的运动轨迹,并运用Monte Carlo方法,求得电子在磁场中的分布,得到电子分布的均值和标准差。本文通过在基片和靶材间加正向电场,改变了电子的运动轨迹和空间分布,优化了矩形平面靶的刻蚀形貌,提高了靶材利用率。     

圆柱旋转双面矩形磁控溅射靶磁场的设计计算

本文提出一种新型的圆柱旋转双面矩形磁控溅射靶,它具有平面磁控溅射靶的优点.根据靶的结构与工作原理,给出了圆柱双面矩形磁控靶磁场强度计算数学模型及计算公式.依据该计算方法,对具体的靶进行了计算机编程计算,并根据计算结果绘制出了靶磁场分布曲线.计算结果表明圆柱双面矩形磁控靶的磁场分布比较均匀,磁场强度满足磁控溅射功能的需要,其靶的溅射刻蚀区可宽达40°角的范围.从而提高了膜层的沉积速率及膜层沉积范围,改善了同轴圆柱形磁控靶由于环状磁场所引起的膜层不够均匀及靶材利用率低的问题,可以在靶磁场两侧的大面积平面基片上沉积出膜厚均匀的涂层.     

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2016年第1期第80页)b.组合磁路改进磁场结构,用组合磁场代替传统的单一磁场,其目的是更有利于放电的稳定(离化率高)和增宽靶材的刻蚀区,提高靶材的利用率。图42是传统磁控源的磁场结构原理图。为单一磁路系统,磁力线的方向都是垂直靶面的,依靠磁力线在空间弯曲,在拱形磁力线的顶部形     

新型双弯曲磁过滤阴极真空电弧沉积系统的磁场模拟计算

本文用ANSYS软件对新型的45°双弯曲磁过滤阴极真空电弧沉积系统中的磁场分布进行了模拟计算,并结合等离子体传输和电弧源弧斑运行稳定性进行了分析。在建立的数学模型基础上,分别研究了磁过滤弯管磁场空间分布对拟定的不同出射方向上的111个碳离子束的传输行为影响,和外加永久磁体对电弧源附近磁场空间分布的影响。结果表明,在优化的磁过滤弯管磁场空间分布情况下,111个碳离子束流可全部通过磁过滤弯管,并高效传输到基材表面。当电弧靶源后部的外加永久磁体磁化方向与弯管上的磁化方向相反,且磁矫顽力大于600 kA/m时,阴极靶弧源附近的磁力线空间分布更利于控制阴极弧斑长时间运行稳定性,这对延长弧斑寿命、提高等离子体的沉积效率、提高靶材表面刻蚀均匀性和获得高性能的ta-C薄膜生长具有重要理论意义。     

磁控溅射带电粒子的运动分布以及靶面刻蚀形貌的研究

首先使用有限元分析方法求解磁控溅射电磁场的分布,然后结合受力分析,仿真了单电子运动轨迹并较好地呈现螺旋形状,同时模拟出多粒子柬的靶面位置分布以及刻蚀形貌图,最后把计算结果与实验中靶面刻蚀形貌进行对比,所求结果与实验测量数据吻合.     

Computer-aided development of a magnetron source with high target utilization

Target erosion in the straight section of a conventional and a novel rectangular magnetron cathode is simulated and tested. The simulation includes modeling the magnetic field, tracing electron trajectories with a fourth-order Runge-Kutta numerical method, predicting ionization distribution with a Monte-Carlo method etc. It is shown that the conventional and the novel magnetron cathodes yield a target utilization of ∼32% and 67% in the straight section, respectively. We demonstrate that the highly improved utilization is mainly due to a multi-zero-point feature of the magnetic field in the novel magnetron, i.e., the position of zero-point for the vertical component of the magnetic flux density shifts continuously from the inner side to outer side of the target with an increase in the distance from the target surface.     

Simulation to improve the magnetic field in the straight section of the rectangular planar DC magnetron

For the rectangular planar DC magnetron, Gaussian type erosion profile may occur in the straight section of target and lead to lower target utilization. Considering the influence of magnetic field on the trajectories of energetic electrons, the target erosion profile and deepest eroded position are analyzed, and then the approaches of magnetic field improvement are proposed. Based on this, two magnet structures with AlNiCo and SmCo are discussed, which could be improved by fitting a shunt bar. According to 2D non-self-consistent particle simulation and Yamamura/Tawara formula, the target erosion profile could be predicted. Via the simulation, the approaches of magnetic field improvement are verified. In the same order of magnetic field intensity, the horizontal component of the magnetic field with wider distribution and larger concavity is proved to make the target utilization much increased.     

Wide erosion nickel magnetron sputtering using an eccentrically rotating center magnet

A wide erosion magnetron sputtering system for nickel targets has been developed using a large, tall and eccentrically rotating center magnet. In this system, a water cooling unit was attached behind the target except the moving center magnet area. Therefore, the rotating mechanism of yoke magnet could be separated from the cooling water without decreasing the magnetic flux on the target surface and ensure a high reliability of long life use.Utilization on the 5-inches Ni target was 40%, as compared with 12% utilization of the conventional system. The sputtering rate and erosion depth linearly changed while the target was in use, because the increase of magnetic flux was lower than that of a conventional system. Hence, the target life will be precisely managed by the total sputtering time.     

磁控溅射靶的磁路设计

磁控溅射是现代最重要的镀膜方法之一，具有简单，控制工艺参数精确和成膜质量好等特点。然而也有靶材利用率低、成膜速率低和离化率低等缺点。研究表明磁场结构对上述问题有重要影响，本文介绍了一种磁控溅射靶磁路优化设计方案。并对改进的磁场结构和一般的磁场结构进行了分析比较，并给出了实验结果。     

磁控溅射薄膜生长全过程的计算机模拟研究

本文通过建立多尺度模型,结合模拟了磁控溅射中溅射原子的产生、溅射原子的碰撞传输、以及最终成膜的全过程,研究了基板温度、溅射速率、磁场分布和靶材-基板间距对薄膜生长过程与薄膜性能的影响.模拟结果显示,提高基板温度或降低溅射速率都会增加初期生长阶段薄膜的相对密度;磁场对靶的利用率有显著的影响,而对薄膜最终形貌的影响不大;增大靶材-基板间距会降低薄膜的粗糙度.     

Target utilization of planar magnetron sputtering using a rotating tilted unbalanced yoke magnet

The dependence of the magnetic flux density, erosion uniformity, and target utilization on the yoke magnet tilt angle was investigated in a planar magnetron sputtering system, using a rotating, tilted, unbalanced, asymmetrical magnet. In these experiments, circular and elliptical outer yokes were used as the rotating yoke magnet. The magnetic flux density distributions were measured two-dimensionally on the target surface and compared with the erosion uniformity. As the yoke magnet tilt angle increased, the magnetic flux density distribution expanded and became more uniform, and the eroded areas expanded toward the outside of the target surface. With a circular outer yoke, as the yoke magnet tilt angle increased from 0° to 8°, utilization of a 5-inch target linearly increased from 60 to 80%. On the other hand, with an elliptical outer yoke, the utilization of the target was approximately 70%, regardless of the yoke magnet tilt angle. This is because, as the tilt angle is increased, the inner area of the target eroded more deeply, while the outer area eroded less deeply. The deposition rate when using the elliptical outer yoke was 1.2 times faster than that of when using the circular outer yoke at the same magnet tilt angle. By decreasing the magnetic flux density on the inner area of the target with an elliptical outer yoke magnet, a higher deposition rate may be obtained than is observed with a circular magnet, and target utilization of over 70% can be achieved.     

一种新型复合加速离子注入动力学研究

提出了一种基于靶台(工件)二次加速的束线离子注入的新方法,基本原理是将传统束线离子注入和等离子体离子注入有效复合。采用二维Particle-in-cell(PIC)模型对这种注入方法进行了数值仿真研究。考察了靶台加负偏压情况下靶台表面空间电势、离子密度变化以及离子的运动状态的时空演化。统计分析了不同时刻离子注入剂量、注入能量和注入角度的分布规律。结果表明:靶台施加偏压对束流离子起到了很好的二次加速效果,束线离子复合加速离子注入这种新方法理论上是切实可行的。同时发现在靶台附近空间电场的作用下,离子束会发生小角度偏转,由柱状形逐渐变成"喇叭口"形,靶台表面有效注入范围扩大。靶台表面注入剂量分布呈中心区域高边缘区域低的趋势。这种新方法有助于减缓电源硬件加工的难度,增加了工艺的灵活性。     

旋转圆柱靶磁控溅射阴极的磁场模拟及结构设计

基于旋转圆柱靶磁控溅射阴极的工作原理,建立其结构模型,并应用ANSYS有限元方法对旋转靶阴极磁场进行了模拟计算,得到了磁场分量Bx在靶材表面上的二维磁场分布规律。通过调节磁铁的宽和高、磁铁间夹角以及设置可移动磁性挡板等方法优化磁场并设计了一种新型磁场结构旋转靶。本研究为旋转靶磁控溅射阴极的磁场结构设计提供了理论依据。     

Pipe internal grooving using closed magnetic field system: A novel method

The present work proposes an innovative method to form microgrooves on a tube's internal surface through new machining based on the principle of the closed magnetic circuit. A newly designed machine with a magnetic grooving tool was fabricated. The tool consists of a pair of magnets positioned in the pipe to be pulled by another pairing magnet set at the pipe's external side, arranged in sequence of N−S−N−S direction so that it creates a closed magnetic field that has a greater pulling force. By controlling the magnet pair at the pipe's external side in the linear and rotational direction, the magnetic grooving tool is moved in both directions and simultaneously pulled towards the pipe surface to form the microgrooves. The experiment was carried out by adjusting the magnet's size combination and its distance to vary the magnetic strengths. The grooving dimension was examined by using an optical microscope and analysed using a 3-dimensional laser profilometer surface analyser. With N52 class Nd₂Fe₁₂B neodymium (40×10×10 mm³), the maximum groove depth of 75.51 μm was recorded and the minimum depth of 2.33 μm was recorded by using magnet size 10×10×10 mm³. The method is capable to produce microgrooves on the copper pipe's internal surface.     

A theoretical study of the impact of magnetic field of Hall current on the parameters of a high-current vacuum-arc discharge

It is demonstrated that the magnetic field of Hall current in a short high-current vacuum-arc discharge significantly distorts the external axial magnetic field and affects the distribution of current density in the discharge gap. This effect decreases with increasing external magnetic field, with decreasing arc current, and with decreasing ratio of the length of discharge gap to its transverse dimension. A 2D magnetohydrodynamic mathematical model is used to calculate the discharge parameters for different values of induction of external magnetic field. The calculation results are compared with similar results obtained using a 1.5D model in which the impact made by magnetic field of Hall current is ignored. It is inferred that the simpler 1.5D model may be employed in calculations of parameters of vacuum arc in a wide range of variation of arc current and of induction of external magnetic field.