磁控溅射靶材刻蚀特性的模拟研究

Computer simulation of the target etching characteristics in magnetron sputtering

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 particlein 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。

Target etching characteristics are the key factors to investigate target utilization, film growth speed and film quality. In this paper, a technique to investigate etching characteristics was performed with the computer simulation . ANSYS, OOPIC Pro（objeet oriented particle in cell） and SRIM（stopping and range of ions in matter） softwares were used to simulate magnetic field distribution, discharge process and sputtering, respectively. Etching profile and etching rate variation with gas pressure and cathode voltage were discussed. The results show that the target profile depends on magnetic field strongly. The position of a maximum etching on the target coincides with the position where the magnetic flux density is maximum. Target etching rate increases with the cathode voltage. While the gas pressure increases, the target etching rate increases and then tends to balance. When the pressure is higher than a certain value, the etching rate begins to decrease with the increase of pressure. The simulation results have a good agreement with experimental measurement.