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用磁控溅射法在单晶硅和聚酰亚胺衬底上制备了恒定调制比(η=1)、调制周期λ=10～100 nm的Cu/Mo纳米多层膜,运用XRD,HRTEM,EDX,AFM,单轴拉伸系统、显微硬度仪和电阻仪对多层膜的微观结构、表面形貌和力学及电学性能进行了研究。结果表明,Cu/Mo多层膜中的Cu层和Mo层分别具有Cu(111)和Mo(110)择优取向,Cu层呈柱状纳米晶、Mo层为极细纳米晶结构,Cu/Mo层间界面处存在一定厚度的扩散混合层。Cu/Mo多层膜的结构和性能受到调制周期和Cu层厚度的显著影响。在调制比η=1的条件下,随着调制周期的增加,软相Cu层厚度增大,Cu/Mo多层膜总体的屈服强度和显微硬度明显下降,裂纹萌生临界应变εc和电导率则显著上升。主要原因在于,随Cu层厚度的增加,Cu晶粒尺寸增大,Cu层内晶界密度降低,使Cu层的位错运动阻力减小、塑性变形能力增强,Cu层内电子散射效应减弱。同时当Cu/Mo多层膜总厚度恒定时,多层膜中Cu层和Mo层的层间界面数量亦随Cu层厚度的增加而减少,减弱了层间界面的电子散射效应,从而使多层膜电导率得以提高。
A Cu / Mo nano-multilayer with a constant modulation ratio (η = 1) and a modulation period λ = 10-100 nm was prepared by magnetron sputtering on monocrystalline silicon and polyimide substrates. XRD, HRTEM , EDX, AFM, uniaxial stretching system, microhardness tester and resistance meter were used to study the microstructure, surface morphology and mechanical and electrical properties of multilayer films. The results show that the Cu and Mo layers have Cu (111) and Mo (110) preferred orientations respectively, the Cu layer has a columnar nanocrystal, the Mo layer has a very fine nanocrystalline structure, and the Cu / Mo layer Between the interface there is a certain thickness of the diffusion mixing layer. The structure and performance of the Cu / Mo multilayers are significantly affected by the modulation period and the Cu layer thickness. With the modulation ratio η = 1, the thickness of the soft Cu layer increases with the increase of the modulation period, the yield strength and microhardness of the Cu / Mo multilayers decrease obviously, and the critical crack initiation ε c and conductivity Then significantly increased. The main reason is that as the thickness of Cu layer increases, the grain size of Cu increases and the grain boundary density decreases in Cu layer, which makes the resistance of dislocation movement of Cu layer decrease, the plastic deformation ability increases and the electron scattering effect in Cu layer weakens. At the same time, when the total thickness of the Cu / Mo multilayers is constant, the number of interlaminar layers of the Cu and Mo layers in the multilayers decreases with the increase of the thickness of the Cu layer, which reduces the electron scattering effect at the interface between the layers, Film conductivity is increased.