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研究了轴对称磁场对电弧离子镀弧斑运动的影响规律, 利用有限元分析软件FEMM对轴对称磁场的分布进行了模拟, 采用SHT-V型磁场测试仪测试了磁场强度, 分析了靶面不同磁场分量的分布规律. 从电弧斑点放电的物理机制出发, 探讨了不同磁场分量和轴对称磁场对电弧离子镀弧斑运动的影响机制. 结果表明, 轴对称磁场通过影响空间正电荷密度n⁺的分布而作用于弧斑运动; 随着轴对称磁场横向分量的增加, 电弧斑点由随机运动逐渐转变为向靶面边缘扩展的旋转运动, 弧斑运动速度加快, 电弧电压升高, 电流下降; 当横向分量增加到临界强度(B_T≈30 Gs)时,弧斑在靶材边缘稳定的快速旋转运动并在靶沿处上下抖动, 弧斑分裂, 靶面中心处每隔0.5 s左右出现多个细的圆斑线, 然后很快向外扩展消失; 靶材边缘出现明显的刻蚀轨道.

Arc ion plating (AIP) has been widely utilized in the deposition of various kinds of thin solid films due to the excellent characteristics of the arc plasma produced from an active cathode spot that emits ions of cathode material, as well as electrons. In AIP process, the cathode spot is usually steered by an external magnetic field. Cathode spot motion is the key factor because it affects the physical characteristics of the vacuum arc plasma, the utilization of the cathode material, the emission of macroparticles (MPs) and the quality of subsequent films containing these MPs. Therefore, cathode spot dynamics should be understood practically under a compound external magnetic field, such as in axisymmetric magnetic field (AMF), for industrial applications. An AMF produced by using an adjustable electromagnetic coil associated with a concentric magnetic flux guider was applied to the cathode surface to investigate the influence of the AMF on the arc cathode spot motion. The distribution of the magnetic field was simulated by the finite element method (FEM) software. The magnetic field intensity was measured by an SHT-V magnetometer and the distributions of magnetic field with different intensities were analyzed. Based on the results of FEM simulation and the physical mechanism of the arc cathode spot discharge, the effects of magnetic-field components and AMF on the cathode spot movement were discussed. The results showed that increasing the AMF intensity can strongly influence cathode spot movement. In the case of a weak AMF,  the cathode spot moves randomly on the cathode surface. With increasing AMF, there is an increasing tendency for the cathode spot to rotate and drift toward the cathode target edge. The increase in the transverse magnetic field (TMF) intensity, B_T, can accelerate the rotational velocity of the cathode spot, increase the arc voltage and decrease the arc current. With a relatively strong AMF (B_T≈30 Gs), the cathode spot rotates near the edge of the cathode surface and is confined to a circular trajectory. A new arc cathode spot is ignited, splits, and is extinguished repeatedly on the cathode surface, which can be observed at intervals of about 0.5 s, while there is an obvious erosion track left at the bottom of the cathode edge.