电子电镀铜新体系中添加剂对铜电沉积及镀层结构的影响机制  

Effects of Additive on the Electrodeposition and Coating Structure in a Novel System of Electronic Copper Electroplating

作　　者：李威青 金磊 杨家强 王赵云 杨防祖[1] 詹东平[1] 田中群[1] LI Weiqing;JIN Lei;YANG Jiaqiang;Wang Zhaoyun;YANG Fangzu;ZHAN Dongping;TIAN Zhongqun(College of Chemistry and Chemical Engineering,State Key Laboratory of Physical Chemistry of Solid Surfaces,Engineering Research Center of Electrochemical Technology,Ministry of Education,Xiamen University,Xiamen 361005,China)

机构地区：[1]厦门大学化学化工学院,固体表面物理化学国家重点实验室,电化学技术教育部工程研究中心,厦门361005

出　　处：《高等学校化学学报》2021年第9期2919-2925,共7页Chemical Journal of Chinese Universities

基　　金：国家自然科学基金(批准号:21972118,21827802,22021001,22132003)资助.

摘　　要：以低主盐浓度、弱碱性、复合配位的柠檬酸盐电子电镀铜新体系为研究对象,阐明了新型添加剂XNS(聚胺类化合物和含氮化合物的混合物)在新电沉积铜体系中的作用.恒电流沉积实验结果表明,添加剂XNS能够提高铜沉积的电流效率,特别是在2.0 A/dm^(2)电流密度下,添加剂XNS使铜沉积电流效率达到95.4%,提高了17.5%.电化学实验的结果表明,添加剂XNS改变了铜沉积的电极过程,由原来的两步单电子还原过程[Cu(Ⅱ)+e→Cu(Ⅰ)+e→Cu]转变为一步两电子还原过程[Cu(Ⅱ)+2e→Cu].虽然添加剂XNS呈现促进铜电沉积的特征,即还原电流增大,但铜镀层颗粒却更细小、更致密均匀.在2.0 A/dm2电流密度下,铜镀层晶体结构由无添加剂时的(111)晶面重构为高择优取向的(200)晶面.Electronic copper electroplating has important applications in the advanced electronic manufactu-ring industry.In this work,the effects of the additive XNS(a mixture of polyamine and nitrogen-containing compounds)on the coating structure in the novel,weakly alkaline and citrate-based multi-coordination system for copper electronic electroplating with low concentration of main salts(10 g/L copper sulfate)was investiga-ted.The constant current deposition experiments indicate that the additive XNS can increase the current efficiency of copper electrodeposition,which achieves 95.4%at a current density of 2.0 A/dm^(2) and increases by 17.5%comparing to the electroplating system without XNS.Electrochemical experiments prove that the additive XNS can change the cathodic reduction of Cu(Ⅱ)cations,i.e.,in presence of XNS which is a one-step two-electron process[Cu(Ⅱ)+2e→Cu],and in absence of XNS which is a two-step one-electron processes[Cu(Ⅱ)+e→Cu(Ⅰ)+e→Cu],and improves the reduction current density of Cu electrodeposition.Although additive XNS can accelerate copper electrodeposition rate,the coating surface of Cu becomes much finer and neater.At the current density of 2.0 A/dm^(2),the crystal structure of copper coating is reconstructed from Cu(111)facet to Cu(200)facet,presenting highly preferred crystal orientation in the presence of XNS.

关 键 词：电子电镀铜 添加剂 复合配位体系 弱碱性低浓度工艺 晶面高择优取向 

分 类 号：O646[理学—物理化学]