摘要
基于二维有限元算法使用COMSOL软件对圆形复合式磁控溅射阴极的磁场进行了计算,结合Matlab优化工具箱分别采用遗传算法和模拟退火算法对圆形复合式磁控溅射阴极的结构进行优化,得到靶材利用率达到最大的最优结构.对得到的最优化磁控阴极,基于自洽粒子模拟方法,使用VSim软件对不同工况下的放电特性进行了模拟.研究发现随着磁场非平衡度的增加,阴极表面电势降落最大的位置和等离子体聚集的位置,沿着阴极表面外沿不断向阴极中心移动,阴极表面磁场的强度不断减小.随着磁场非平衡度的增加,等离子体密度先增加后减小,鞘层厚度先减小后增加,等离子体的密度和鞘层厚度不仅与磁场非平衡度有关,而且与磁场强度有关.最后根据粒子模拟的结果,对复合式磁控阴极的靶材刻蚀深度进行了研究.研究发现,在优化前后靶材的刻蚀范围从60 mm扩展至整个靶面,极大地提高了靶材利用率.
Based on the two-dimensional finite element method,＇ the magnetic field of circular composite magnetron sputtering cathode is calculated by COMSOL software. The genetic algorithm and simulated annealing algorithm combined with Matlab optimization toolbox are used to optimize the structure of circular composite magnetron sputtering cathode, and the structural parameters with the largest utilization rate of target are obtained. For the resulting optimized magnetron cathode, based on the self-consistent particle simulation method, the discharge characteristics under different working conditions are simulated by VSim software. It is found that with the increase of non-equilibrium degree of magnetic field, the cathode surface potential drops to the maximum position and the location of the plasma aggregation, moving from the outer surface of the cathode to the center, the intensity of the magnetic field on the cathode surface decreases When the two coils have no currents flowing, the density of the plasma is largest and the thickness of the sheath is smallest In the two coils there flow reverse 5 A currents, the non-equilibrium magnetic field reaches a maximum value and the thickness of sheath is largest, the corresponding electric field strength is weak, which is not conducive to the impact ionization, so the plasma density is smallest However, in the two coils there flow positive 5 A currents, and the non-equilibrium magnetic field is smallest, the plasma density and the sheath thickness are not only related to the non-equilibrium magnetic field, but also to the magnetic field strength. Finally, according to the results of particle simulation, the target erosion depth of the magnetron cathode is studied. Combined with the sputtering yield curve, the curve of etching depth of the cathode target surface is obtained. It is found that the erosion range of the target extends from 60 mm to 76.2 mm （target radius） before and after optimization. By adjusting the magnitudes and directions of currents in the two coils, all the target surfaces can be etched, which greatly improves the target utilization.
作者
汪天龙
邱清泉
靖立伟
张小波
Wang Tian-Long1）2） Qiu Qing-Quan1） Jing Li-Wei1） Zhang Xiao-Boa） 1）(Applied Superconductivity Key Laboratory, Chinese Academy of Sciences, Institute of Electrical Engineering of the Chinese Academy of Sciences, Beijing 100190, China） 2） （ University of Chinese Academy of Sciences, Beijing 100049, China） 3） （ SuPro Instruments Company Limited, Shenzhen 518035, China)
出处
《物理学报》
SCIE
EI
CAS
CSCD
北大核心
2018年第7期99-107,共9页
Acta Physica Sinica
基金
国家自然科学基金(批准号：51277172)和国家自然科学基金创新研究群体科学基金(批准号：51721005)资助的课题.
关键词
磁控阴极
优化设计
磁场非平衡度
放电
magnetron cathode, optimization design, non-equilibrium, discharge
