TTA-K与pH值对Ru阻挡层Cu互连图形片CMP的影响  

Effect of TTA-K and pH Value on CMP of Patterned Wafer with Ru as Barrier Layer and Cu Interconnect

作　　者：张雪[1] 周建伟 王辰伟 Zhang Xue;Zhou Jianwei;Wang Chenwei(College of Information and Electrical Engineering,Heilongjiang Bayi Agricultural University,Daqing 163000,China;School of Electronic Information Engineering,Hebei University of Technology,Tianjin 300130,China)

机构地区：[1]黑龙江八一农垦大学信息与电气工程学院,黑龙江大庆163000 [2]河北工业大学电子信息工程学院,天津300130

出　　处：《微纳电子技术》2022年第4期385-391,共7页Micronanoelectronic Technology

基　　金：国家自然科学基金资助项目(62074049)。

摘　　要：研究了甲基苯并三氮唑钾盐(TTA-K)与pH值协同作用对Ru基阻挡层Cu互连图形片Cu膜化学机械平坦化(Cu CMP)后碟形坑及蚀坑的影响。静态腐蚀实验结果表明,Cu静态腐蚀速率和Cu去除速率随TTA-K体积分数增加而显著降低,随抛光液pH值增加而显著上升。即TTA-K对Cu静态腐蚀有明显的抑制作用,但TTA-K对Cu的抑制效果随抛光液pH值升高而逐渐减弱。图形片Cu CMP结果表明,在抛光液pH值为9时,仅体积分数0.1%的TTA-K即可将线宽和线间距分别为100μm和100μm的碟形坑深度由350 nm降低到70 nm,将线宽和线间距分别为9μm和1μm的蚀坑深度由250 nm控制在60 nm,且满足Cu和Ru去除速率比大于100∶1的工艺要求,具有较强的平坦化性能。X射线光电子能谱(XPS)结果表明其平坦化机理为TTA-K与Cu形成钝化膜附着在Cu表面,阻挡了抛光液进一步腐蚀。The effect of the synergy of methyl benzotriazole potassium salt(TTA-K) and pH value on the dishing and erosion of copper interconnect patterned wafer with Ru-based barrier layers after copper chemical mechanical planarization(Cu CMP) was investigated. Static corrosion test results show that Cu static corrosion rate and Cu removal rate obviously decrease with the increase of volume fraction of TTA-K, while obviously increase with the increase of pH value of polishing slurry. That is, TTA-K has obvious inhibition on the static corrosion of Cu, but inhibitory effect of TTA-K on copper decreases gradually with the increase of pH value of polishing slurry. The CMP results of copper patterned wafer show that when the pH value of slurry is 9, the dishing depth with a line width of 100 μm and a line spacing of 100 μm is reduced from 350 nm to 70 nm, and the erosion depth with a line width of 9 μm and a line spacing of 1 μm is controlled from 250 nm to 60 nm by using polishing slurry with TTA-K volume fraction of 0.1%, which meets the process requirements that the removal rate ratio of Cu and Ru is greater than 100∶1, and has strong planarization performance. The X-ray photoelectron spectroscopy(XPS) results indicate that the planarization mechanism is that a passive film is formed with TTA-K and copper and adheres to the copper surface to prevent further corrosion of polishing slurry.

关 键 词：化学机械平坦化(CMP) 钌阻挡层 铜图形片 碟形坑 蚀坑 

分 类 号：TN305.2[电子电信—物理电子学]