高稀释倍数碱性铜精抛液在Cu CMP中的应用  

Application of a High Dilution Ratio Alkaline Copper Clearing Slurry for Cu CMP

作　　者：曹阳[1] 刘玉岭[1] 王辰伟[1] 高娇娇[1] 陈蕊[1] 蔡婷[1] 

机构地区：[1]河北工业大学微电子研究所,天津300130

出　　处：《半导体技术》2013年第8期614-617,628,共5页Semiconductor Technology

基　　金：国家科技重大专项资助项目(2009ZX02308)

摘　　要：采用自制的不含常用的腐蚀抑制剂(BTA)碱性铜精抛液对铜和钽进行了化学机械抛光。研究了高稀释倍数(50倍)的精抛液对铜膜的静态腐蚀速率和抛光速率以及钽抛光速率的影响,并对65 nm技术节点的300 mm单层铜布线片进行了平坦化研究。结果表明,铜膜的静态腐蚀速率为1.5 nm/min,动态抛光速率为206.9 nm/min,阻挡层Ta/TaN抛光速率仅为0.4 nm/min,Cu/Ta选择比高。此精抛液能够有效去除残余铜,进一步过抛完全去除残余铜时,对阻挡层的去除速率趋于0,而沟槽里的铜布线去除量低,碟形坑和蚀坑大小满足实际平坦化要求。此精抛液可满足65 nm技术节点平坦化的要求。An alkaline copper clearing slurry without common corrosion inhibitors benzotriazole （BTA） for Cu and Ta chemical mechanical polishing was successfully developed. Effect of high dilution （50X） copper clearing slurry on the removal rate and the selectivity of Cu/Ta was investigated, the planarization properties of the slurry in 300 mm copper pattern wafer with 65 nm node were also studied. Experiment results show that the dissolution rate of copper is 1.5 nm/min, the polishing rate of Cu is 206.9 nm/min and barrier films such as Ta/TaN is just 0.4 nm/min, the selectivity ratio of Cu to Ta is higher. Copper residual can be effectively removed by using the copper clearing slurry, barrier films have low polishing rate which tends to 0, and Cu wiring in the trench has low removal rate when copper residual is completely removed. After the copper clearing polishing step, the value of dishing and erosion can meet the requirement of the 65 nm technology copper interconnects industry.

关 键 词：铜布线 精抛液 高稀释倍数 碟形坑 化学机械抛光(CMP) 

分 类 号：TN305.2[电子电信—物理电子学]