铝溅射沉积速率与刻蚀槽深度变化关系研究

Impact of Sputtered Groove Depth in Al-Target on Deposition Rate: An Experimental and Simulation Study

采用磁控溅射法制备铝膜是微电子工艺制备金属薄膜最常用的工艺之一,然而在使用磁控溅射设备制备铝膜时,往往会发现调用同一个工艺菜单,制备出的铝膜厚度会有所不同,最大相差接近40%。这对于制备高精度膜厚的铝膜具有严重的影响。我们研究发现在相同的工艺条件下,铝膜的溅射速率随着靶材的消耗先增加,后降低。通过研究靶材刻蚀槽的形状,利用磁力线分布的变化和"空心阴极效应"理论解释了溅射速率产生变化的原因,并根据大量的统计数据,利用Origin软件模拟出铝膜溅射速度与刻蚀槽深度之间的关系公式。这为教学实验、真空镀膜工艺和集成电路生产领域高精度溅射铝膜提供参考。

We addressed the problem of non-constant deposition-rate in growth of Al coatings by magnetron sputtering. The influence of the Al-target consumption,or the depth of the sputtered grooves,on the deposition-rate of Al coatings was mathematically modeled,theoretically analyzed in electromagnetics and ＂hollow cathode effect＂theories,and experimentally investigated. The results show that the groove depth in Al-target significantly affected the deposition-rate. For example,as the Al-consumption increased,the deposition-rate changed in an increase-decrease mode,resulting in a largest thickness difference by 40%. Possible mechanism was tentatively discussed. The analytical dependence of the Al-coating thickness,grown under the fixed conditions,on the groove depth was derived by statistical analysis of the measured results and with Origin simulation software. We suggest that the results we reported be of some technological interest in synthesis of Al coatings by magnetron sputtering.