氨基乙酸-H_2O_2体系抛光液中铜的化学机械抛光研究  

Chemical Mechanical Polishing of Copper in Glycine-H_2O_2 System Slurry

作　　者：张伟[1] 路新春[1] 刘宇宏[1] 潘国顺[1] 雒建斌[1] 

机构地区：[1]清华大学摩擦学国家重点实验室,北京100084

出　　处：《摩擦学学报》2008年第4期366-371,共6页Tribology

基　　金：国家重点基础研究发展计划资助项目(2003CB716201);国家自然科学基金委与广东省政府自然科学联合基金资助项目(2003CB716201);国家自然学基金资助项目助项目(50775122)

摘　　要：在CP-4型CMP试验机上采用5μm厚的铜镀层片研究了氨基乙酸-H2O2体系抛光液中铜的化学机械抛光行为,分别采用Sartorius 1712MP8型电子天平和WYKO MHT-Ⅲ型光干涉表面形貌仪检测抛光去除率和抛光后表面粗糙度,用CHI660A型电化学工作站的动电位极化扫描技术和PHI-5300ESCA型X射线光电子能谱仪分析抛光液中氧化剂和络合剂等化学组分对铜的作用机制.结果表明,由于氧化剂H2O2对铜的氧化作用使得氨基乙酸对铜的络合速率从1.4 nm/min提高到47 nm/min,进而提高了铜的化学机械抛光去除率.当抛光压力≤10.35 kPa时,抛光后铜表面出现腐蚀坑,腐蚀坑面积比率随抛光过程相对运动速度的增大而减小;当抛光压力≥17.25 kPa时,铜表面腐蚀坑消失,在相对运动速度≥1 m/s条件下,表面粗糙度为3-5 nm;当抛光压力〉6.9 kPa,在相对运动速度≤1 m/s条件下,随着相对运动速度增大,机械作用增强,抛光去除率增大;当相对运动速度〉1 m/s时,抛光界面区抛光液润滑效应增强,抛光去除率有所降低,化学机械抛光过程中这一临界相对运动速度为1 m/s.Chemical mechanical polishing behavior of copper in glycine-H2O2 system slurry was studied. The polishing experiment was performed on polishing test-bed CP-4, and the samples used were electrochemical deposited copper film with 5μm in thickness. The material removal rate and surface profile of the specimens were evaluated by Sartorius 1712MP8 electron balance and surface profile apparatus individully. Also the chemical mechanisms of slurry components were studied by XPS and potential scan technique on a electrochemical workstation. Results show that, glycine complexed with Cu effectively via the oxidized film on the copper surface and then improved the material removal rate. Because of the chemical effect of polishing slurry, when the polishing pressure was lower than 10.35 kPa, pits occured on the polished surface. With the polishing pressure increased to larger than 17.25 kPa, pits disappeared and the surface roughness reached to 3 -5 nm. Also, relative velocity in the polishing process played an important role. When the polishing pressure was larger than 6.9 kPa, before the velocity increased to 1 m/s, material removal rate increased with the velocity, and if the velocity was larger than 1m/s, because of the lubricant behavior during the polishing interface, the material removal rate decreased a little. During this process, the critical velocity was 1m/s.

关 键 词：化学机械抛光 动电位极化扫描 氨基乙酸 腐蚀坑 

分 类 号：TN305.2[电子电信—物理电子学] TH117.3[机械工程—机械设计及理论]