添加剂对微盲孔铜沉积的影响研究

Effect of additives on copper electrodeposition for microvia filling

采用恒电流（GM）电化学方法研究了电镀添加剂（3-巯基-1-丙烷磺酸钠（SPS）、环氧乙烷／环氧丙烷嵌段聚合物（EO／P05800）、3-羧基-1-（苯基甲基）吡啶翁氯化钠（BN—Betaifie））相互作用及其对铜沉积电位的影响，运用循环伏安（cV）技术分析了添加剂在电极表面的吸附以及旋转圆盘电极（RDE）转速、添加剂浓度对覆盖率的影响。包含0．0001％SPS、O．02％~O／PO、O．001％BN—Betaine的酸性镀铜液用于盲孔铜沉积测试，分析了电镀填孔在不同时期（初始期、爆发期、末期）盲孔填充性能变化规律。借助多物理场耦合平台，建立微盲孔铜沉积模型，用有限元方法讨论了电镀铜过程，获得铜沉积速率变化规律，结论与实验结果一致。

The interactions among additives employed in acidic copper plating solution for microvia filling and effect on the copper deposition potential was characterized by galvanostatic measurement （GM）. The adsorption behavior and surface coverage of additives with various concentrations under different rotation speeds of working electrode were investigated by cyclic voltammetry （CV） measurement. Microvia filling by copper electrodeposition was carried out using acid plating bath containing lppmSPS, 200ppm and 10ppmBN-Betaine. According to SEM images of microvia at the different times, evolution of the shape of microvia and variation of the electrodeposition rate at the bottom of microvia and surface were analyzed. Further, a microvia filling model was constructed using a multi-physics coupling technology based on the finite element method. Modeling result was presented and compared with the measured data, which was in good agreement with the experiments.