芯片钴互连及其超填充电镀技术的研究进展  

Research Progresses of Cobalt Interconnect and Superfilling by Electroplating in Chips

作　　者：魏丽君 周紫晗 吴蕴雯 李明[1] 王溯 Li-Jun Wei;Zi-Han Zhou;Yun-Wen Wu;Ming Li;Su Wang(College of Materials Science and Engineering,Shanghai Jiao Tong University,Shanghai 200240,China;Shanghai Sinyang Semiconductor Materials Co.,Ltd.,Shanghai 201616,China)

机构地区：[1]上海交通大学材料科学与工程学院,上海200240 [2]上海新阳半导体材料股份有限公司,上海201616

出　　处：《电化学》2022年第6期18-30,共13页Journal of Electrochemistry

基　　金：国家自然科学基金项目(No.62004124,No.61376107)资助。

摘　　要：芯片中的钴互连作为铜互连之后的下一代互连技术受到了业界的极大关注,且已经引入集成电路7 nm以下的制程。钴互连主要采用湿法的电化学沉积技术,但由于保密原因和研究条件的限制,其研究报道不多。本文基于现有专利、文献报道较系统地介绍了钴互连技术的优势及发展现状,并从溶液化学和电化学角度综述了钴互连电镀基本工艺、基础镀液组成与添加剂、超填充电镀机理,以及镀层退火控制与杂质影响等的研究现状,并对钴互连技术下一步研究进行了展望。Copper interconnect using dual damascene technology has always been the main means for metallization in the back end of line process.However,with the size effect becoming more and more obvious due to feature size reduction,copper interconnect can no longer meet the demand for high circuit speed in Post-Moore era.Following copper interconnection,cobalt interconnection in chips attracts much attention as an interconnect technology by the next generation,which has been introduced in 7 nm node of integrated circuit manufacturing and below.The electron mean free path of cobalt(~10 nm)is much shorter than copper’s(39 nm),thus exhibiting the potential to further shrink the critical dimension without increasing line resistance and RC delay especially for contacts or local interconnects in the first few stack layers.Also,cobalt is considered as a suitable barrier/liner material,which means implementing cobalt interconnects needs no such layers and gives more space for conductive metal.Besides,higher melting point of cobalt makes it more favorable with good electromigration resistance compared with copper interconnects.Cobalt interconnection mainly adopts the wet electrodeposition method and the quality of the electrodeposite matters a lot to the reliability of the metal interconnects.For the reason of confidentiality and the limitation of research conditions,there are few research reports about cobalt interconnection.Based on existing patents and literature reports,this paper systematically introduces the advantages and current developments of cobalt interconnection.To better understand the behavior of the metal ions during electroplating process,this paper reviews the basic technology,bath composition and additives used in the electrolyte for cobalt electroplating from the point of view of solution chemistry and electrochemistry.For superconformal electroplating,there are several superfilling mechanisms for bottom-up electrodeposition with different emphasis,this paper gives a brief summary about three mechanisms and m

关 键 词：钴 电沉积 超填充 互连 自下而上 

分 类 号：TN405.97[电子电信—微电子学与固体电子学]