摘要
针对在浅沟槽隔离(STI)化学机械抛光(CMP)过程中,氧化铈抛光液稳定性差、易团聚等问题,研究了pH值和聚丙烯酸(PAA)对氧化铈磨料稳定性的影响。结果表明,在pH值为4.5的条件下,氧化铈磨料中加入质量分数0.1%的PAA后,Zeta电位值为-40.68 mV。使用紫外可见分光光度计测试的吸光度值为0.448,验证了0.1%PAA对氧化铈磨料分散性最佳。其次,通过PAA与PVA、PVP对氧化铈磨料分散稳定性能和抛光结果的对比,发现氧化铈磨料中加入0.1%PAA稳定性可以维持到24 h,并通过扫描电子显微镜(SEM)观察氧化铈粒径分布均匀未发生团聚现象;使用添加PAA的氧化铈抛光液在CMP后可以明显提高SiO2/Si3N4的去除速率选择比。研究结果表明,一定浓度的PAA有助于在氧化铈颗粒之间形成空间位阻效应,提高了氧化铈抛光液的稳定性,对STI CMP抛光液的应用具有重要意义。
Aiming at the problems of poor stability and easy agglomeration of the cerium oxide slurry in shallow trench isolation(STI)chemical mechanical polishing(CMP)process,the effects of pH value and polyacrylic acid(PAA)on the stability of the cerium oxide abrasive were studied.The results show that under the condition of pH=4.5,the Zeta potential value is-40.68 mV after adding 0.1%PAA to the cerium oxide abrasive.The absorbance value tested by Ultraviolet-Visible Spectrophotometer is 0.448,which verifies that the PAA with a mass fraction of 0.1%has the best dispersion of the cerium oxide abrasive.Secondly,by comparing the dispersion stability and polishing results of the cerium oxide abrasives with PAA,PVA and PVP,it is found that the addition of PAA with a mass fraction of 0.1%can maintain the stability for 24 h,and the particle size distribution of the cerium oxide is uniform and no agglomeration was observed by scanning electron microscope(SEM).The removal rate selectivity of SiO2/Si3 N4 can be significantly improved by using cerium oxide slurry with PAA after CMP.Based on the experimental results,it is studied and proposed that a certain mass fraction of PAA is helpful to form a steric hindrance effect between the cerium oxide particles,which improves the stability of the cerium oxide slurry.This is of great significance for the application of STI CMP slurry.
作者
张国林
王胜利
罗翀
王辰伟
刘德正
ZHANG Guolin;WANG Shengli;LUO Chong;WANG Chenwei;LIU Dezheng(School of Electronic and Information Engineering,Hebei University of Technology,Tianjin300130,China;Tianjin Key Laboratory of Electronic Materials and Devices,Tianjin300130,China)
出处
《电子元件与材料》
CAS
北大核心
2023年第11期1355-1361,共7页
Electronic Components And Materials
基金
国家自然科学基金(62074049)。
关键词
氧化铈
化学机械抛光
聚丙烯酸
稳定性
去除速率
cerium oxide
chemical mechanical polishing
polyacrylic acid
stability
removal rate
