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％.     

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。     

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.     

圆形平面磁控溅射靶的设计

本文提出一种设计圆形平面磁控溅射靶的《等效电流磁场计算法》，实测证明，用该法计算的磁感应强度Ｂ的分布及其规律可以作为设计圆形平面磁控溅射靶的依据。如靶的几何参数、永久磁铁的剩磁、靶──基片距离、靶与周围零件的设置及屏蔽罩的安装位置等。由于掌握了磁感应强度Ｂ的分布及大小，因而可方便地确定诸如电压、功率、气压等参数。 为改善圆形平面磁控溅射靶的性能，提高靶材利用率，本文还介绍了三种改进型靶的设计方案。     

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。     

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...     

第十九讲 真空溅射镀膜

<正>(接2016年第3期第80页)由于工作时是匀速旋转的,因而不但溅射更加均匀,靶材利用率也大大提高,一般的平面磁控溅射靶的靶材利用率极低(不足20%),而这种结构靶材利用率超过70%。     

真空离子镀金靶材的镶嵌复合工艺与靶型的研制

本文介绍了金靶材与阴极背板结合时所采用的镶嵌复合工艺，以及利用这种工艺对矩形或圆柱形磁控溅射靶进行金靶材形状的改进，最终可使金靶材的利用率提高到７０％～８０％。而且这种工艺也适用于金合金靶材与阴极背板的结合上，因此这一制靶工艺的开发，对真空离子镀金技术的进一步推广和应用具有十分重要的意义     

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.     

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     

The erosion energy efficiency of sputtering

A new parameter of sputtering, the erosion energy efficiency, is defined as the ratio of the theoretical energy required to eject atoms to the experimental energy. This efficiency η (E) is shown to be proportional to the ratio of the sputtering yield Y(E) to the energy E and, even under optimum conditions never exceeds ～ 10%. The relationship of this efficiency to the broadening process occurring during sputter profiling resulting from recoil atomic motion and mixing is examined. It is shown that the ion energy conditions employed in both technological etching and sputter profiling systems are near optimum for energy utilization and profile broadening minimization.     

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.     

磁控溅射镀膜设备中靶的优化设计

磁控溅射已发展为工业镀膜生产中最主要的技术之一。对在镀膜批量生产中普遍存在的靶材利用率、溅射速率和沉积速率低以及溅射过程不稳定等突出问题，固然可用优化电源设计和调整工艺参数等加以改善，但根本的问题在于整个系统，特别是靶的优化设计。本文简要评述了已有靶的典型设计及其特点；对靶分析和设计的通行方法，包括电磁场有限元、等离子体粒子模型及流体模型、以及设计过程中其它一些需要注意的问题作了讨论。鉴于国内目前在靶的分析设计方面与国际先进水平之间还存在着比较大的差距，希望能够引起有关方面的重视。     

Some New Views on the Principles of Magnetron Sputtering

In this paper, some common phenomena in magnetron sputtering are freshly analyzed and discussed on the basis of the motion of electrons in non-uniform orthogonal electric and magnetic fields. There exist magnetic confinements in three spatial dimensions on moving charged particles (including electrons) in this kind of non-uniform field. They are the longitudinal cycloidal motion, the horizontal simple harmonic-like motion (with varying amplitudes), and the vertical repelling action. The horizontal magnetic confinement in a mirror-like magnetic field keeps glow discharge lane completely parallel to the corridor of magnetic force lines, therefore only an effectively closed magnet array structure can form a relatively uniform and closed discharge lane. The main reasons for electrons' releasing from magnetic confinement are the vertical magnetic repelling force as well as a more and more weak confinement action in outer range etc. The dominant reasons for a comparatively low increase of substrate's temperature are that the density of bombarding electrons near the substrate is relatively low and their spatial distribution is relatively uniform (compared with that near the target surface). The erosion lane with an inverted Gauss's distribution shape on a magnetron sputtered target is due to that,with sputtering, the distribution width of the critical density of electrons shrinks continuously but the sputtering effect in the centerline of the corridor is always the most powerful.     

Argon ion etching in a reactive gas

It is shown that the sputtering yield of various materials submitted to argon ion (1 ke V) bombardment decreases strongly with increase of oxygen pressure in the atmosphere of the sputtering chamber. The sputtering yields are plotted against the “poisoning ratio” (the poisoning ratio is defined as the ratio of the rate of arrival of oxygen molecules at the target surface to that of the rate of removal of sputtered atoms). On the curves representing the sputtering yield versus the poisoning ratio, two particular values are pointed out for each material. Between these two values the sputtering yield decreases as the poisoning ratio increases, out of these values the sputtering yield is quite independent of the poisoning ratio. In the region of high poisoning ratio value, the spread of the sputtering yield for investigated materials is wider than in the region of low poisoning ratio value. Thus, we observed, in terms of etching rate, a ratio of 7 between silica and chromium and a ratio of 10 between silica and vanadium when the oxygen pressure introduced in the target chamber is 10⁻⁴ Torr. These results are used in order to obtain deep grooves in silica, when such metals are used as masking materials. New data on the sputtering yield of various materials is provided.     

Ring etching zones on magnetron sputtering targets

A practical and theoretical investigation into a method for estimating the forms and dimensions of etching zones on magnetron sputtering targets is presented. This estimation is based on detailed geometry considerations of the internal arrangement of the vacuum chamber and the sputtering parameters. It is proved theoretically and experimentally that etching zones on sputtering targets are in a ring shape and that their location and dimensions are independent on the target material or dimensions.     

Large area ZnO:Al films with tailored light scattering properties for photovoltaic applications

Aluminum-doped zinc oxide films on glass are promising substrates for use in thin film solar cells based on amorphous and amorphous/microcrystalline silicon absorber material. The films can be produced by magnetron sputtering on large scale at relative low cost. Especially reactive sputtering of metallic Zn/Al compound targets is a cheap way to produce films at high deposition rate. One drawback of amorphous silicon is the low absorption in the near infrared spectral range. Wet chemical etching has been used to produce a rough TCO surface that enables light trapping in the absorber. The etching behaviour of ZnO:Al films can be tuned by changing oxygen partial pressure during deposition. The etching behaviour is compared to ZnO structure and discussed regarding the performance of solar cells deposited onto the etched films.