工艺参数对阻挡层CMP后互连线厚度一致性的影响  

Effects of process parameters on thickness uniformity of chemical mechanical polished barrier layer for copper interconnect

作　　者：王海英 王辰伟 刘玉岭 赵红东 WANG Haiying;WANG Chenwei;LIU Yuling;ZHAO Hongdong(School of Electronic and Information Engineering,Hebei University of Technology,Tianjin 300130,China;Tianjin Key Laboratory of Electronic Materials and Devices,Tianjin 300130,China;Science and Technology on Electro-Optical Information Security Control Laboratory,Tianjin 300308,China)

机构地区：[1]河北工业大学电子信息工程学院,天津300130 [2]天津市电子材料与器件重点实验室,天津300130 [3]光电信息科学与工程控制和安全技术重点实验室,天津300308

出　　处：《电子元件与材料》2023年第11期1370-1376,共7页Electronic Components And Materials

基　　金：国家自然科学基金(62074049);天津市科技计划项目(21YDTPJC00050);光电信息控制和安全技术重点实验室基金(2021JCJQLB055008)。

摘　　要：为了有效控制铜互连阻挡层化学机械平坦化(CMP)后互连线厚度(THK),优化其一致性,研究了抛光液流量、边缘压力及抛光时间等工艺参数对铜(Cu)、介质(TEOS)去除速率,以及对图形片CMP后THK一致性的影响。采用无氧化剂H2O2、无缓蚀剂BTA的弱碱性抛光液对阻挡层材料进行抛光实验,实验结果表明:采用抛光液流量为250 mL/min,抛光压力P1/P2/P3/P4/P5为33.37/13.72/13.24/12.55/11.58 kPa,抛光时间为40 s+20 s的拆分抛光工艺条件下CMP时,得到THK为224.9 nm,片内非均匀性(With-In Wafer Non-Uniformity,WIWNU)为0.92%,极差(Range)为7.82 nm,满足工业生产要求,基于实验结果,还发现此工艺条件下的铜表面形貌更优(表面粗糙度Sq=1.71 nm),对提高CMP后的平整度及可靠性具有重要意义。In order to effectively control the interconnect thickness(THK)of the copper interconnection barrier layer chemical mechanical polishing(CMP)and optimize its uniformity,the effects of the polishing fluid flow rate,edge pressure and polishing time on the removal rate of copper(Cu),oxide(TEOS)and interconnect thickness uniformity of CMP of online wafer were studied.CMP of barrier material was carried out in a weakly alkaline slurry without oxidant(H2O2)and inhibitor(BTA).The experimental results show that with polishing fluid flow rate of 250 mL/min,edge pressure P1/P2/P3/P4/P5 of 33.37/13.72/13.24/12.55/11.58 kPa,and polishing time of 40 s+20 s,THK is 224.9 nm,With-In Wafer Non-Uniformity is 0.92%,Range is 7.82 nm.Based on the experimental results,it is also found that the surface morphology of copper under splitting process is better,the surface roughness is 1.71 nm,which is of great significance to improve the flatness and reliability of CMP.

关 键 词：铜互连 阻挡层 工艺参数 互连线厚度 去除速率 

分 类 号：TG175[金属学及工艺—金属表面处理]