不同表面活性剂对浅沟槽隔离CMP中SiO_(2)与Si_(3)N_(4)速率选择性的影响  

Effects of different surfactants on the removal rate selectivity of SiO_(2)and Si_(3)N_(4) in shallow trench isolation CMP

作　　者：张月 周建伟 王辰伟 郭峰 ZHANG Yue;ZHOU Jianwei;WANG Chenwei;GUO Feng(School of Electronic and Information Engineering,Hebei University of Technology,Tianjin 300130,China;Tianjin Key Laboratory of Electronic Materials and Devices,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]天津市电子材料与器件重点实验室,天津300130

出　　处：《电子元件与材料》2023年第5期578-583,共6页Electronic Components And Materials

基　　金：国家自然科学基金(62074049)。

摘　　要：针对浅沟槽隔离(STI)化学机械抛光(CMP)过程中SiO_(2)与Si_(3)N_(4)去除速率选择比难以实现的问题,研究了阳离子表面活性剂十六烷基三甲基溴化铵(CTAB)、阴离子表面活性剂直链烷基苯磺酸(LABSA)以及非离子表面活性剂脂肪醇聚氧乙烯醚(AEO7)对SiO_(2)与Si_(3)N_(4)去除速率以及速率选择比的影响。结果表明,CTAB对于SiO_(2)去除速率的抑制作用过强,导致速率选择比很低;与CTAB相比,LABSA对SiO_(2)去除速率的抑制作用减弱,但同时对Si_(3)N_(4)去除速率的抑制作用也变小,导致速率选择比无法满足工业生产的30∶1的要求;AEO7对SiO_(2)去除速率的影响较小,且对Si_(3)N_(4)去除速率的抑制作用强于LABSA。当引入质量分数为0.05%的AEO7时,SiO_(2)的去除速率由318.6 nm/min降低至224.1 nm/min,Si_(3)N_(4)的去除速率由28.6 nm/min降低至7 nm/min,速率选择比达到了32∶1,对于提高抛光效率以及有效地保护有源区具有重要意义。To address the difficulty of achieving high removal selectivity of SiO_(2)and Si_(3)N_(4) in shallow trench isolation(STI)chemical mechanical polishing(CMP),cationic surfactant cetyltrimethylammonium bromide(CTAB),anionic surfactant linear alkylbenzene sulfonic acid(LABSA)and nonionic surfactant fatty alcohol polyoxyethylene ether(AEO7)were studied to understand their effect on the removal rate and selectivity of SiO_(2)and Si_(3)N_(4).The results show that CTAB strongly inhibits the removal rate of SiO_(2),resulting in a very low selectivity.In contrast to CTAB,LABSA has less inhibition on the removal rate of SiO_(2)and Si_(3)N_(4) as well,which cannot meet the selectivity requirement of 30∶1 for industrial production.AEO7 can rarely affect the removal rate of SiO_(2),however,can have stronger inhibition effect on the removal rate of Si_(3)N_(4) than that of LABSA.When AEO7 has a mass fraction of 0.05%,the removal rate of SiO_(2)decreases from 318.6 nm/min to 224.1 nm/min,and it decreases from 28.6 nm/min to 7 nm/min for Si3 N4,where the selectivity can reach 32∶1.It can greatly improve the polishing efficiency and protect the active area with the selectivity of 32∶1.

关 键 词：浅沟槽隔离 化学机械抛光 表面活性剂 速率选择比 

分 类 号：TN405[电子电信—微电子学与固体电子学]