磁控溅射Cu膜屈服强度的有限元计算

采用离子辅助轰击共溅射设备，在Si基体的(111)晶面上制得了所需的铜膜。采用纳米压入实验，获得不同退火温度下Cu膜的弹性模量和硬度。再在纳米压入实验的基础上，结合有限元模型计算不同退火温度下磁控溅射得到的Cu膜屈服强度。发现Cu膜的屈服强度远高于整体Cu材料的屈服强度，并且退火温度对薄膜的屈服强度影响很大。通过XRD测量发现其主要原因是退火改变了晶粒尺寸和多晶Cu膜的晶粒取向分布，而导致Cu膜屈服强度的降低。

The Yield Strength Calculated by Finite Element Method for Sputtered Cu Film

The Cu thin films on (111) of Si substrate were prepared by the co-sputtering equipment of ion beam enhance deposition, using the nano-indentation experiments, the elastic moduli and hardnesses of Cu films at different annealing temperature were obtained. The yield strength of Cu film was calculated by FEM model based on the nano-indentation experiments. It is found that yield strength of Cu film is much higher than that of bulk of Cu. And the annealing temperature affects the yield strength of film greatly. From XRD spectrum, it is analyzed that the decrease of yield strength of Cu film results from the change of crystal size and crystal plane.