基于电子理论Ni基体上电沉积Cu膜内应力研究

Research on Internal Stress in Electrodeposited Cu Films on Ni Substrates Based on Electron Theory

摘要:

采用电沉积法在Ni基体上制备Cu膜。悬臂梁法在线测量沉积Cu膜后的Ni基片挠度，由测得的挠度值计算出Cu膜内的平均内应力和分布内应力。结果表明，Cu膜内的平均内应力和分布内应力均随膜厚的增加而急剧减小。膜内的界面应力很大，而生长应力很小。基于改进的Thomas-Feimi-Dirac-Cheng(TFDC)电子理论，对由于界面电子密度调整而引起的Cu膜内平均内应力作出了初步估算。结果表明，理论估算结果与实验结果较接近。这说明理论计算模型具有较高的准确性

Abstract:

Electroplating was employed to prepare Cu film on the surface of Ni substrate. Deflection of Ni substrate with Cu film coating was measured in situ by a cantilever beam method. Based on the measured deflection, average internal stress and distributed internal stress in Cu film were calculated. The results show that average internal stress and distributed internal stress in the Cu film decrease abruptly with the thickness of Cu film increasing. Interfacial stress of Cu film is very large while growth stress is small. Average internal stress in Cu film, which is caused by the adjustment of the electron densities at both sides of the interface, was roughly calculated using the modified Thomas-Feimi-Dirac-Cheng (TFDC) electron theory. The calculated result of TFDC electron theory is close to that of the experiment, indicating that the calculation model of electron theory is of high accuracy