化学添加剂提高钴化学机械抛光性能的研究进展

Research Progress of Chemical Additives for Improving Performance of Cobalt Chemical Mechanical Polishing

钴(Co)具有电阻率低、电子迁移率高、对铜(Cu)等金属的黏附性好以及沉积性能好等优势,在集成电路制程中作为Cu互连阻挡层或新型互连材料具有巨大的应用潜力,而金属互连化学机械抛光(CMP)是决定Co在集成电路应用中可靠性的关键工艺。概述了抛光液中的不同化学添加剂提高Co抛光性能的研究进展,重点介绍了氧化剂、络合剂、腐蚀抑制剂等化学添加剂对Co阻挡层和Co互连CMP的材料去除速率(MRR)、静态腐蚀速率(SER)、去除速率选择比以及电偶腐蚀的影响。讨论了化学添加剂对提高Co抛光性能的作用机理,并分析了加入不同化学添加剂的抛光液的优势与不足。此外,展望了Co阻挡层和互连材料CMP工艺中仍需进一步研究的问题。

Cobalt(Co)has a great application potential as a copper(Cu)interconnection barrier layer or a new interconnection material in integrated circuit manufacturing for the advantages of low resistivity,high electron mobility,good adhesion to Cu and good deposition performance.Chemical mechanical polishing(CMP)of metal interconnection is the key process to determine the reliability of Co in integrated circuit applications.The research progress of different chemical additives in slurries to improve the polishing performance of Co is reviewed.The effects of chemical additives such as oxidants,complexing agents,corrosion inhibitors on the material removal rate(MRR),static etching rate(SER),removal rate selectivity and galvanic corrosion of Co barrier layer and Co interconnect CMP are emphatically introduced.The mechanism of chemical additives to improve the polishing performance of Co is discussed,and the advantages and disadvantages of slurries with different chemical additives are also analyzed.In addition,the problems that need further research in the study of CMP process of Co used in barrier layer or interconnection material are prospected.