新型碱性阻挡层抛光液在300mm铜布线平坦化中的应用
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摘要
研发了一种新型碱性阻挡层抛光液,其不含通用的腐蚀抑制剂和不稳定的氧化剂(通常为H2O2)。Cu/Ta/TEOS去除速率和选择性实验结果表明,此阻挡层抛光液对Cu具有较低的去除速率,能够保护凹陷处的Cu不被去除,而对阻挡层(Ta)和保护层(TEOS)具有较高的去除速率,利于碟形坑和蚀坑的修正。在300mm铜布线CMP中应用表明,此碱性阻挡层抛光液为高选择性抛光液,能够实现Ta/TEOS/Cu的选择性抛光,对碟形坑(dishing)和蚀坑(erosion)具有较强的修正作用,有效地消除了表面的不平整性,与去除速率及选择性实验结果一致,能够用于多层铜布线阻挡层的抛光。
In this paper,we have developed an alkaline barrier slurry for barrier removal applied in copper chemical mechanical planarization(CMP).Firstly,we have studied the characteristics of removal rate and selectivity of Ta/TEOS/Cu under the same process condition.The results indicate that copper has a low removal rate during barrier CMP by using this slurry,it will protect the copper films from directly dissolution,Ta and TEOS has high removal rate selectivity to Cu,thus it may be helpful to modify the dishing and erosion.The pattern wafer results reveal that the alkaline barrier slurry has a strong modify effect on dishing and erosion reduction,and can be useful applied in barrier CMP.
In this paper,we have developed an alkaline barrier slurry for barrier removal applied in copper chemical mechanical planarization(CMP).Firstly,we have studied the characteristics of removal rate and selectivity of Ta/TEOS/Cu under the same process condition.The results indicate that copper has a low removal rate during barrier CMP by using this slurry,it will protect the copper films from directly dissolution,Ta and TEOS has high removal rate selectivity to Cu,thus it may be helpful to modify the dishing and erosion.The pattern wafer results reveal that the alkaline barrier slurry has a strong modify effect on dishing and erosion reduction,and can be useful applied in barrier CMP.
引文
[1]Hu Yi,Liu Yuling,Liu Xiaoyan,et al.Effect of nano-SiO2slurry on low-k material(PI)[J].Journal of Func-tional Materials,2011,42(s5):852-854.
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[7]Jacqueline J P,Alone E,Yalicheff C,et al.Norman don,Tan/Ta belayed barrier characteristics and integration for90and 65nm nodes[J].Microelectronic Engineering,2005,82(3-4):613-617.
[8]Zantye P B,Kumar A,Sikder A K.Chemical mechanicalplanarization for microelectronics applications[J].Mate-rials Science and Engineering,2004,45:89-220.
[9]Vijayakumar A,Du T,Sundaram K B,et al.Selectivitystudies on tantalum barrier layer In copper CMP[J].Ma-terials Research Society,2003,767:1-6.
[10]Chang S H.A dishing model for chemical mechanicalpolishing of metal interconnects structures[J].Micro-electronic Engineering,2005,77(1):76-84.
[2]Liu Xiaoyan,Liu Yuling,Liang Yan,et al.Function ofnano-SiO2slurry for chemical mechanical polishing in al-kaline media[J].Journal of Functional Materials,2010,41(11):1903-1906.
[3]Nguyen V H,Daamen R,Hoofman R.Impact of differ-ent slurry and polishing pad choices on the planarizationefficiency of a copper CMP process[J].MicroelectronicEngineering,2004,76:95-99.
[4]Krishnan M,Nalaskowski J W,Cook L M.Chemicalmechanical planarization:slurry chemistry,materials andmechanisms[J].Chemical Reviews,2010,110(1):178-204.
[5]Zantye P B,Kumar A,Sikder A K.Chemical mechanicalplanarization for microelectronics applications[J].Mate-rials Science and Engineering,2004,45(3-6):89-220.
[6]Our K L,Wu C C,Hsu C C,et al.Reliability of multi-tasked tantalum-based structure as the barrier film in ul-tralargescale integrated metallization[J].MicroelectronicEngineering,2005,81:44-52.
[7]Jacqueline J P,Alone E,Yalicheff C,et al.Norman don,Tan/Ta belayed barrier characteristics and integration for90and 65nm nodes[J].Microelectronic Engineering,2005,82(3-4):613-617.
[8]Zantye P B,Kumar A,Sikder A K.Chemical mechanicalplanarization for microelectronics applications[J].Mate-rials Science and Engineering,2004,45:89-220.
[9]Vijayakumar A,Du T,Sundaram K B,et al.Selectivitystudies on tantalum barrier layer In copper CMP[J].Ma-terials Research Society,2003,767:1-6.
[10]Chang S H.A dishing model for chemical mechanicalpolishing of metal interconnects structures[J].Micro-electronic Engineering,2005,77(1):76-84.