电解液温度和pH值对铜电沉积行为及性能的影响

Effects of Electrolyte Temperature and pH Value on Behavior and Properties of Electrodeposited Copper

通过循环伏安(CV)和计时电流(CA)实验研究了电解液温度和pH值对铜电结晶行为的影响,并采用X射线衍射仪(XRD)、扫描电子显微镜(SEM)、三维超景深显微镜和显微硬度计分析了电解液温度和pH值对铜电沉积层的相成分、择优取向、微观结构、粗糙度和硬度的影响。结果表明,铜电结晶过程均为受扩散控制的三维形核生长模式。当电解液温度为35℃时,铜的电沉积效率最高;电解液pH值为9时,对铜的电沉积促进作用最优。不同电解液温度和pH值最终的成核机制均为三维瞬时成核生长。随着电解液温度的升高和pH值的降低,择优取向由(111)晶面转变为(220)晶面。当电解液温度为35℃,pH为9时,可获得具有平整致密、粗糙度和硬度良好的铜电沉积层。

The effects of temperature and pH value of electrolyte on the electrochemical crystallization behavior of copper was investigated through cyclic voltammetry(CV)and chronoamperometry(CA)experiments.The effects of electrolyte temperature and pH value on the phase composition,preferred orientation,microstructure,roughness,and hardness of copper electrodeposited layers were analyzed by XRD,SEM,three-dimensional ultra depth of field microscopy and microhardness tester.The results indicate that the copper electrocrystallization process is a three-dimensional nucleation and growth mode controlled by diffusion.When the electrolyte temperature is 35℃,the electrodeposition efficiency of copper is the highest;when the pH value of the electrolyte is 9,the promotion effect on copper electrodeposition is optimal.The final nucleation mechanism of copper deposition layer at different electrolyte temperatures and pH values is three-dimensional instantaneous nucleation growth.With the increase in electrolyte temperature and the decrease in pH value,the preferred orientation changes from(111)crystal plane to(220)crystal plane.When the electrolyte temperature is 35℃and pH is 9,a flat,dense,rough and hard electrodeposited copper layer can be obtained.