磁控溅射制备磁性多层膜中SiO_2/Ta界面的研究

Study of the SiO_2/Ta Interface in Magnetic Multilayers Prepared byMagnetron Sputtering

磁性多层膜常用磁控溅射的方法制备,并且以金属Ta做为缓冲层。本研究利用这种方法在单晶硅基片上沉积了Ta/NiFe/Ta薄膜。采用X射线光电子能谱(XPS)对该薄膜进行了深度剖析,并且对获得的Ta 4f和Si 2p的高分辨率XPS谱进行计算机谱图拟合分析。结果表明:磁控溅射这种高能量制膜技术导致了在SiO2/Ta界面处发生了化学反应:15SiO2＋37Ta=6 Ta2O5＋5 Ta5Si3,该反应使得界面有“互混层”存在,从而导致诱发NiFe膜(111)织构所需的Ta缓冲层实际厚度的增加。从本研究还可以看出XPS是表征磁性薄膜界面化学状态的一种有利工具。

Magnetic multilayers are often prepared by magnetron sputtering, and Ta is used as the buffer layer. In this study, Ta/NiFe/Ta multilayers were deposited on single-crystal Si substrate. XPS depth profiling and peak decomposition technique was used to study the film. The results show that the high-energy deposited technique resulted in an 'intermixing layer' at the SiO2/Ta interface due to a thermodynamically favorable reaction: 15 SiO2 + 37 Ta = 6 Ta2O5 + 5 Ta5Si3 . Therefore, the Ta buffer layer thickness used to inducing NiFe (111) texture increase. We can also see from the study that XPS is shown to be a powerful tool in characterizing the chemical states in magnetic multilayers.