N′,N′-二乙基硫脲添加剂对铜微沉积工艺电化学行为的影响  

Effects of N',N'-Diethylthiourea on Electrochemical Behavior of Copper Micro-electrodeposition

作　　者：张涛[1] 吴一辉[2] 杨建成[1] 张平[2] 

机构地区：[1]天津工业大学机械电子学院,天津300160 [2]中国科学院长春光学精密机械与物理研究所,长春130033

出　　处：《化学学报》2008年第21期2434-2438,共5页Acta Chimica Sinica

基　　金：国家自然科学基金(No.60574089);天津工业大学青年基金(No.029735)资助项目

摘　　要：为了研究N',N'-二乙基硫脲添加剂在微沉积工艺中对铜金属孔洞填充能力的影响,采用线性伏安法(LSV)、循环伏安法(CV)、SEM测量法分析比较了无添加剂、含硫脲和含N',N'-二乙基硫脲添加剂时微沉积铜工艺中的电化学行为,并借助塔菲尔方程,分析比较此三种情况下电镀反应过程中的电极动力学参数.结果显示:当铜微沉积工艺中加入N',N'-二乙基硫脲添加剂时,产生活性极化,该活性极化效应降低铜离子的放电速度,抑制孔洞边缘部分沉积较快区域的过快生长;同时活性极化提高,将导致成核点的增加,沉积膜的晶粒较小,镀膜也较平滑细致,实验测得铜离子的平滑能力比没有添加剂时提高约50%.最后通过微沉积工艺成功地将金属铜填充入宽为10μm,深宽比为4∶1的微型凹槽中,且镀层内没有空洞、空隙以及细缝等缺陷.In order to investigate the copper gap-filling during micro electroplating process with additive （N′,N′-diethylthiourea）, the electrochemical behavior of different electrolyte （without additive, with thiourea or N′,N′-diethylthiourea additive） were studied by LSV, CV and SEM, and the electrode kinetics parameters was studied by the Tafei equation. The results show that when N′,N′-diethylthiourea was used during the micro electroplating copper process, activation polarization was generated; metal ion discharge rate was low- ered, the overgrowth of fast plating area such as micro-trench edges was restrained; at the same time, activa- tion polarization was increased, thus the crystal nucleus molding speed on the electrode was accelerated; the crystal growth speed was decreased, the plating became flat, and the leveling ability was increased about 50% than that without additive. Furthermore, some micro trenches in the silicon wafer, and the width of 10 μn and aspect ratio of 4 ： 1, were filled by the micro electroplating process with the additive N′,N′-diethylthiourea, however, the electroplating layer had no voids or seams.

关 键 词：微沉积工艺 N′ N′-二乙基硫脲 活性极化 电化学行为 

分 类 号：TG174.4[金属学及工艺—金属表面处理]