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.     

磁控溅射靶磁场的有限元模拟分析

磁控溅射靶面磁感应强度的水平分布直接关系到靶材的利用率和刻蚀的均匀性,为了寻求更好的磁控靶结构参数,从而实现靶面水平磁感应强度的均匀分布,本文应用COMSOL软件对JGP450C型磁控溅射镀膜机的圆平面靶表面磁感应强度进行了模拟分析计算,得到了靶面水平磁感应强度较强、分布较均匀的磁铁结构参数。     

直流磁控溅射中磁场强度和阴极电压对圆平面靶刻蚀形貌的影响

本文借助Comsol和Matlab软件模拟了直流磁控溅射圆平面靶系统的磁场分布和荷电粒子分布,对不同磁场强度和阴极电压条件下的荷电粒子分布进行了模拟分析,通过比较靶面离子流密度分布曲线发现:当磁场强度增强时,靶面离子流密度分布曲线会变得更加陡窄;当阴极电压变化时,靶面离子流密度分布曲线几乎没有变化.说明靶材的刻蚀形貌会随磁场强度增强而变窄,而阴极电压变化对靶材的刻蚀形貌没有影响.上述结论对直流磁控溅射工艺参数优化具有一定的理论指导意义.     

磁控溅射中旋转阴极的对角效应及其解决途径

对角效应是一种存在于磁控溅射中,由于阳极的不对称分布而引起的一种不对称刻蚀的现象,表现为靠近阳极的一侧溅射跑道沿着霍尔电流方向的转角刻蚀明显增强,而另一侧对应转角刻蚀相对较弱,如为双靶时,表现为沿对角线方向刻蚀增强的现象,导致靶材的不均匀刻蚀及靶材利用率降低.文章研究了这种现象,对其成因进行了分析,并进一步阐明了如何避...     

新型等离子体束溅射镀膜机

本文介绍了新型的等离子体束溅射镀膜机的系统组成、特点、试验结果等内容.该镀膜机将等离子体发生和控制技术应用于溅射镀膜中,克服了磁控溅射的靶材利用率低及难以沉积铁磁性材料的缺点.使用该镀膜机成功地进行了溅射镀膜的试验,试验结果得到了刻蚀均匀性较高的靶材,其靶偏压与靶电流的关系与国外结果相吻合.     

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。     

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 ,后者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     

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.     

矩形平面磁控溅射装置薄膜沉积仿真

薄膜厚度沿矩形靶长度方向分布的均匀度是衡量矩形平面磁控溅射装置镀膜质量的重要指标。为了分析气压和靶基板间距对该指标的影响,本文采用Monte Carlo方法,在假设靶材沿跑道均匀刻蚀的前提下,对靶材原子沉积过程进行了计算机仿真。模型假设靶材原子出射能量满足Thompson分布,出射角度以余弦定律处理;假设背景气体速度为麦克斯韦分布,并采用舍选法对各个速度分量进行了抽样;应用可变硬球模型对碰撞过程进行了处理。通过仿真发现,随着气压增大,尽管薄膜的均匀度越好,但是靶材原子到达基板的能量会降低;而靶与基板间距越大,薄膜的均匀度和靶材原子到达基板的能量都会降低。另外,通过对矩形靶端部磁场改进,可以削弱靶材的反常刻蚀现象,在提高靶材利用率的同时,可以有效提高薄膜均匀度。     

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。     

阳极磁屏蔽霍尔离子源磁场的数值模拟

为了提高离子束电流和离子束能量,进一步增加霍尔离子源的效率,对霍尔离子源阳极进行磁屏蔽,达到优化磁场位形,增强磁场对放电等离子体的约束。由磁场的数值模拟结果可知:阳极磁屏蔽后,有明显凸向阳极表面的弯曲磁场线,并且提高了磁镜磁场的磁镜比;大的正梯度磁场的存在,增强了磁场的径向分量,相对减弱了放电等离子体的震荡;不仅保留原有鞍形场的作用,而且还充分发挥了另外两个鞍形场的优势。最后通过实验结果和数值模拟结果的比较,验证了此数值模拟结果的正确性。     

平行板反应离子刻蚀系统均匀磁场的数值计算

在平行板反应离子刻蚀系统的圆筒形腔体的侧壁上绕上电流线圈后,系统中的磁场强度和均匀性都可进行调节。本文根据螺线管线圈内部磁场的分布规律,通过数值计算的方法在该系统中获得均匀的磁场。     

圆平面磁控溅射靶磁场的ANSYS模拟分析

磁控溅射靶面磁感应强度的水平分布直接关系到靶材的利用率和刻蚀的均匀性.为了寻求更好的磁控靶结构参数,从而实现靶而水平磁感应强度的均匀分布,作者应用ANSYS软件对SD500型磁控溅射镀膜机的圆平面靶表面磁感应强度进行模拟,应用SHT-V型特斯拉计通过同心十字线法对实物靶表面磁感应强度进行测试,将模拟结果与测量结果进行比较,证明其模拟的准确性.进而对圆平面磁控靶的结构参数进行优化设计,得出靶与磁钢间距为3 mm、磁钢高度为15 mm、内磁柱半径为4 mm、内磁柱高度为14 mm时靶面水平磁感应强度最强、分布最均匀.在工程应用中,设计人员可以预先对靶的参数进行优化设计,使设计的磁控溅射靶更好的满足生产和科学研究的需要.     

<Emphasis Type="Italic">In situ</Emphasis> grazing-incidence small-angle X-ray scattering observation of block-copolymer templated formation of magnetic nanodot arrays and their magnetic properties

The fabrication of bit-patterned media (BPM) is crucial for new types of hard disk drives.The development of methods for the production of BPM is progressing rapidly.Conventional lithography reaches the limit regarding lateral resolution,and new routes are needed.In this study,we mainly focus on the dependence of the size and shape of magnetic nanodots on the Ar+-ion etching duration,using silica dots as masks.Two-dimensional (2D) arrays of magnetic nanostructures are created using silica-filled diblock-copolymer micelles as templates.After the self-assembly of the micelles into 2D hexagonal arrays,the polymer shell is removed,and the SiO2 cores are utilized to transform the morphology into a (Co/Pt)2-multilayer via ion etching under normal incidence.The number of preparation steps is kept as low as possible to simplify the formation of the nanostructure arrays.High-resolution in situ grazing-incidence small-angle X-ray scattering (GISAXS) investigations are performed during the Ar+-ion etching to monitor and control the fabrication process.The in situ investigation provides information on how the etching conditions can be improved for further ex situ experiments.The GISAXS patterns are compared with simulations.We observe that the dots change in shape from cylindrical to conical during the etching process.The magnetic behavior is studied by utilizing the magneto-optic Kerr effect.The Co/Pt dots exhibit different magnetic behaviors depending on their size,interparticle distance,and etching time.They show ferromagnetism with an easy axis of magnetization perpendicular to the film.A systematic dependence of the coercivity on the dot size is observed.     

Ni纳米管阵列的选择性刻蚀法制备及磁性质

采用基于氧化铝模板的电化学共沉积方法合成了Ni/Cu纳米电缆有序阵列,通过电化学选择刻蚀纳米电缆的铜核,制备了多晶Ni纳米管有序阵列。Ni纳米管有序阵列表现出明显的单轴磁各向异性,易磁化轴沿着纳米管方向。这种具有磁各向异性的有序阵列在高密度垂直磁记录材料中具有潜在的应用前景。     

Characterization of magnetic domain walls using electron magnetic chiral dichroism

Domain walls and spin states of permalloy were investigated by electron magnetic chiral dichroism (EMCD) technique in Lorentz imaging mode using a JEM-2100F transmission electron microscope. EMCD signals from both Fe and Ni L_3,2 edges were detected from the Bloch lines but not from the adjacent main wall. The magnetic polarity orientation of the circular Bloch line is opposite to that of the cross Bloch line. The orientations of Fe and Ni spins are parallel rather than antiparallel, both at the cross Bloch line and circular Bloch line.     

Characterization of magnetic domain walls using electron magnetic chiral dichroism

Abstract

Domain walls and spin states of permalloy were investigated by electron magnetic chiral dichroism (EMCD) technique in Lorentz imaging mode using a JEM-2100F transmission electron microscope. EMCD signals from both Fe and Ni L_3,2 edges were detected from the Bloch lines but not from the adjacent main wall. The magnetic polarity orientation of the circular Bloch line is opposite to that of the cross Bloch line. The orientations of Fe and Ni spins are parallel rather than antiparallel, both at the cross Bloch line and circular Bloch line.     

Effect of external magnetic fields on shaped-charge operation

This paper deals with electromagnetic actions that allow one to control the shaped-charge effect at different stages of shaped-charge operation. A decrease in penetration of the shaped-charge jet is attained by production of an axial magnetic field in the shaped-charge liner immediately before shot, and production of a magnetic field in the conducting target material that is transverse to the direction of jet propagation. The considerable decrease in the penetration capability of the charge observed in the experiments is attributed to a sharp amplification of the magnetic field in the jet formation region upon liner collapse. The effects accompanying the “field pumping” prevent the normal formation of a shaped-charge jet. A model of magnetic field generation in a conducting medium subjected to high-velocity deformation with particle elongation along the magnetic flux lines is considered. X-ray photographs of shaped-charge jets formed from a “magnetized liner” are given. Theoretical calculations have shown that deformation conditions that can provide for intense magnetic field generation also arise during high-velocity jet penetration into a conducting target across the flux lines of the initial magnetic field previously produced in the target.     

磁性材料在磁性纸中的应用

介绍了常用磁性材料及其制备方法,综述了细胞腔加填法和原位复合法制备磁性纤维和磁性纸的研究情况,进而对两种方法制备的磁性纸的印刷适应性进行分析。