Sn-Cu薄膜的沉积行为及其微观形貌分析

Analysis of Sn-Cu films deposition behaviors and micromorphologies

利用电沉积法,在酸性镀液中制得Sn-Cu薄膜,采用扫描电子显微镜(SEM)及能谱仪(EDS)研究镀液中主盐浓度、电镀工艺条件及添加剂对薄膜形貌的影响,并借助循环伏安曲线研究不同条件对Sn-Cu沉积行为的影响。研究结果表明:镀液中主盐浓度的增大促进了Sn-Cu的还原沉积;添加剂的引入对金属离子具有较强的螯合作用,限制了镀液中自由金属离子的浓度,使得合金沉积电位负移;此外,镀液中Sn2+浓度变化对镀层晶粒粒度影响较大,改变Cu2+浓度对镀层的平整度影响较大;电流密度增加、温度降低及加入添加剂,都能细化镀层晶粒。

Sn-Cu films were prepared by electrodeposition.The effect of the concentrations of main salts,the process conditions and additives on the morphologies of Sn-Cu films were investigated by scanning electron microscopy（SEM） and energy disperse spectroscopy（EDS）,and the effect of various conditions on electrodeposition of Sn-Cu was investigated by cyclic voltammetry（CV）.The results indicate that the increase of main salts concentrations promotes Sn-Cu reduction deposition.The addition of additives holds metal ions in chelation,restricts the concentration of free metal ions and the deposition potential of Sn-Cu turns to negative direction.The concentration of Sn2＋ has influence mainly on the grain size,while the concentration of Cu2＋ has influence mainly on the planeness of the deposits.The increase of the current density,or the decrease of the bath temperature or the addition of additives can accelerate the growth of fine grains in the deposits.