酸性镀铜添加剂对电沉积循环伏安曲线成核环的影响

Influence of Additives in Acidic Copper Electroplating Bath on Nucleation Loop of Cyclic Voltammetric Curve

金属电沉积的循环伏安(CV)曲线上的成核环可以用于分析添加剂对电沉积的影响及其作用机理。以常用的3种酸性镀铜添加剂为例,探讨了不同添加剂下成核环的形成特点,并从其成核环的位置以及构成成核环的电流曲线来探讨添加剂对铜沉积的影响及其机理。结果表明:当成核环分别位于不加添加剂的阴极电位和阳极电位方向时,添加剂对金属电沉积分别具有阻化和促进作用;阴极扫描方向电流密度Jb和回扫的阳极电流密度Ja是CV曲线成核环的两个特征参数,添加剂作用下的Ja和Jb与不加添加剂的接近,表明添加剂通过吸附-脱附机理影响金属的沉积,反之表明添加剂在电极表面参与化学反应。

With three kinds of typical acidic copper plating additives as examples,the formation characteristics of nucleation loop of cyclic voltammetric curves(CV) were explored,and the location and I-V curves of nucleation loop were used to study the influences and mechanism of additives on the deposition of Cu.Result showed that when the nucleation loop was located at directions of cathode potential and anode potential without additives,adding additives had acceleration effect or inhibition effect on the metal electrodeposition,respectively.At the cathode scan direction,the current density of cathodic scans J_b and return anodic J_n were the two characterized parameters of a nucleation loop.The J_b and J_a with the effect of additives were closed to those without additives,which indicated that the effect mechanism of additive for copper electrodeposition was adsorption-desorption.Conversely,the results would present that the additives participated in chemical reactions on the electrode surface.