蓝宝石衬底CMP中氧化硅磨粒粒度分布对抛光液体系性能影响研究  

Effect of Silica Abrasive Particle Size Distribution on the Properties of Polishing Slurry System in Sapphire Substrate CMP

作　　者：王晓剑 李薇薇 钟荣锋 肖银波 许宁徽 孙运乾 WANG Xiaojian;LI Weiwei;ZHONG Rongfeng;XIAO Yinbo;XU Ninghui;SUN Yunqian(College of Electronic Information Engineering,Hebei University of Technology,Tianjin 300401,China;Guangdong Wellt-Nanotech Co.,Ltd.,Guangdong Dongguan 523000,China)

机构地区：[1]河北工业大学电子信息工程学院,天津300401 [2]广东惠尔特纳米科技有限公司,广东东莞523000

出　　处：《表面技术》2024年第2期168-174,200,共8页Surface Technology

基　　金：光电信息控制和安全技术重点实验室基金(614210701041705)。

摘　　要：目的 化学机械抛光(CMP)包含化学腐蚀和机械磨削两方面,抛光液p H、磨粒粒径和浓度等因素均会不同程度地影响其化学腐蚀和机械磨削能力,从而影响抛光效果。方法 采用30~150 nm连续粒径磨粒抛光液、120 nm均一粒径磨粒抛光液、50 nm和120 nm配制而成的混合粒径磨粒抛光液,分别对蓝宝石衬底晶圆进行循环CMP实验,研究CMP过程中抛光液体系的变化。结果 连续粒径磨粒抛光液中磨粒大规模团聚,满足高材料去除率的抛光时间仅有4 h,抛光后的晶圆表面粗糙度为0.665 nm;均一粒径磨粒抛光液中磨粒稳定,无团聚现象,抛光9 h内材料去除率较连续粒径磨粒抛光液高94.7%,能至少维持高材料去除率18 h,抛光后的晶圆表面粗糙度为0.204 nm;混合粒径磨粒抛光液初始状态下磨粒稳定性较高,抛光9 h内材料去除率较连续粒径磨粒抛光液高114.8%,之后磨粒出现小规模团聚现象,后9h材料去除率仅为均一粒径磨粒抛光液的59.6%,18 h内材料去除率仅为均一粒径磨粒抛光液的87.7%,但抛光后的晶圆表面粗糙度为0.151 nm。结论 一定时间内追求较高的材料去除率和较好的晶圆表面粗糙度选用混合粒径磨粒抛光液,但需要长时间CMP使用均一粒径磨粒抛光液更适合,因此,在工业生产中需要根据生产要求配合使用混合粒径磨粒抛光液和均一粒径磨粒抛光液。Chemical mechanical polishing(CMP) includes chemical corrosion and mechanical grinding.Factors such as pH of polishing slurry,particle size and concentration of abrasive particles will affect its chemical corrosion and mechanical grinding ability to varying degrees,thus affecting the polishing effect.UNIPOL-1200S automatic grinding and polishing machine and SUBA-600 polishing pad were used in the experiment to conduct the cyclic polishing experiment on the 2-inch sapphire substrate wafer in the C-direction of single crystal.30-150 nm continuous particle size abrasive polishing slurry,120nm uniform particle size abrasive polishing slurry,50 nm uniform particle size nano silica and 120 nm uniform particle size nano silica were mixed according to 4:6(volume ratio) to form a mixed particle size abrasive polishing slurry,and 2% chelating agent(citrate),2% oxidant(hydrogen peroxide) and 0.1% surfactant(fatty alcohol polyoxyethylene ether) were added to each type of polishing slurry.The flow rate of polishing slurry was 100 mL/min.The sapphire substrate wafer rotated clockwise at 30rpm.The polishing pad rotated counterclockwise at 60 r/min.The load was 15.5 kg.Three types of polishing slurry were used to conduct cyclic CMP experiments on sapphire substrate wafers to study the changes of polishing slurry system during CMP process.In the continuous particle size abrasive polishing slurry,the abrasive particles aggregated on a large scale,and the polishing time required for high material removal rate was only 4 hours.The surface roughness of the polished wafer was 0.665nm.The abrasive particles in the polishing slurry with uniform particle size were stable without agglomeration.The material removal rate within 9 hours of polishing was 94.7%,higher than that of the continuous particle size abrasive polishing slurry,which could maintain a high value for at least 18 hours.The surface roughness of the polished wafer was 0.204 nm.In the initial state of mixed particle size abrasive polishing slurry,the stability of the abrasive

关 键 词：化学机械抛光 蓝宝石 抛光液 磨粒 微观形貌 材料去除率 

分 类 号：TG175[金属学及工艺—金属表面处理] TG356.28[金属学及工艺—金属学]