锇在甲酸体系抛光液中化学机械抛光研究  

Investigation on Chemical Mechanical Polishing of Osmium in Formic Acid Based Slurries

作　　者：梁淼[1] 储向峰[1] 董永平[1] 张王兵[1] 孙文起[1] 陈均[1] 

机构地区：[1]安徽工业大学,安徽马鞍山243002

出　　处：《半导体技术》2013年第8期609-613,共5页Semiconductor Technology

基　　金：国家自然科学基金项目(50975002);教育部高校留学回国人员科研项目;安徽工业大学创新团队项目(TD201204)

摘　　要：基于金属锇有可能成为大规模集成电路铜互连扩散阻挡层新材料,利用自制的甲酸(HCOOH)体系抛光液对金属锇进行了化学机械抛光研究,利用原子力显微镜(AFM)观察抛光后锇的表面形貌。采用电化学分析方法研究双氧水(H2O2)、HCOOH和苯丙三氮唑(BTA)对样品腐蚀效果的影响。结果表明:当抛光液中仅含H2O2时,金属锇表面腐蚀不明显;而在H2O2-HCOOH体系中,H2O2浓度的增加可使金属锇表面的腐蚀速度明显加快,但不利于金属锇表面钝化膜的形成;缓蚀剂BTA的加入促进了金属锇表面钝化膜的生成,降低了抛光速率,但同时提高了金属锇的表面质量,表面粗糙度Ra由8.0 nm降低到4.2 nm。Osmium is considered as the potential barrier material in copper interconnects of ultra-large scale integration. The osmium was polished by using homemade HCOOH-based slurries. The surface of the wafer was analyzed by means of the atomic force microscopy （AFM）. The effects of the H202, HCOOH and BTA on the corrosion behaviors Were investigated using electrochemical dynamics. The results show that the surface corrosion of osmium is not obvious when the main components in slurry is only H202. In the H2 02- HCOOH based slurries, the increasing of H2 02 concentration promotes the chemical corrosion ability to corrode the surface of osmium, but inhibits the formation of passive film. The addition of BTA decreases the material removal rate because of the presence of passive film At the same time, the polishing conditions can improve the surface quality, and the surface roughness Ra decreases from 8. 0 to 4. 2 nm.

关 键 词：化学机械抛光(CMP) 锇(Os) 甲酸 极化曲线 过氧化氢 抑制剂 

分 类 号：TN305.2[电子电信—物理电子学]