抛光压力与表面活性剂对铜CMP均匀性的影响  

Effects of the Polishing Pressure and Surfactant on the Uniformity in Copper CMP

作　　者：赵亚东[1,2] 刘玉岭[1,2] 栾晓东[1,2] 牛新环[1,2] 王仲杰[1,2] Zhao Yadong Liu Yuling Luan Xiaodong Niu Xinhuan Wang Zhongjie(School of Electronic and Information Engineering Tianfin Key Laboratory of Electronic Materials and Devices, Hebei University of Technology, Tianjin 300130, China)

机构地区：[1]河北工业大学电子信息工程学院,天津300130 [2]河北工业大学天津市电子材料与器件重点实验室,天津300130

出　　处：《半导体技术》2017年第2期119-123,152,共6页Semiconductor Technology

基　　金：国家中长期科技发展规划重大专项资助项目(2009ZX02308);天津市自然科学基金资助项目(16JCYBJC16100);河北省自然科学基金资助项目(E2013202247)

摘　　要：研究了铜化学机械抛光(CMP)过程中,不同压力和非离子型表面活性剂对片内非均匀性(WIWNU)的影响。通过改变抛光压力大小和非离子型表面活性剂浓度,得出WIWNU的变化规律。实验表明,在不同抛光压力下,铜去除速率有明显的变化。当抛光压力为0 psi(1 psi=6.89×103Pa)时,去除速率呈中间高边缘低。当压力为0.5 psi时,边缘处去除速率较高,且随着压力的增大,晶圆边缘处去除速率与晶圆中心处去除速率差将更明显,导致片内非一致性增大。通过添加非离子型表面活性剂,可以改善WIWNU。当压力为1.5 psi时,非离子型表面活性剂体积分数为5%,WIWNU可降低到3.01%,并且得到良好的平坦化结果。同时,非离子型表面活性剂对晶圆表面残留颗粒具有良好的去除作用。The effect of different pressure and nonionic surfactant on the within-wafer nonuniformity（WIWNU） was researched during the Cu chemical mechanical planarization（CMP） process. The change rule of the WIWNU was obtained by changing the polishing pressure and the concentration of the nonionic surfactant. The experimental results indicate that different polishing pressures lead to a remarkable change of the copper removal rate. When the polishing pressure is 0 psi（1 psi = 6. 89×103Pa）,the copper removal rate at the wafer center is higher than that at its edge. When the pressure is 0. 5 psi,the removal rate at the wafer edge is higher. And with the increase of the pressure, the removal rate difference between the edge and the center of the wafer will be more obvious,which will lead to the increase of the WIWNU. By adding the nonionic surfactant,the WIWNU can be improved. When the pressure is 1. 5 psi and the volume fraction of the nonionic surfactant is 5%,the WIWNU can be reduced to 3. 01% and a good planarization result will be obtained. Meantime,the residual particles on the wafer surface can be well removed by using the nonionic surfactant.

关 键 词：化学机械抛光(CMP) 片内非均匀性(WIWNU) 抛光压力 非离子型表面活性剂 铜去除速率 

分 类 号：TN305.2[电子电信—物理电子学]