超精密加工中铜表面CMP后残余金属氧化物的去除  

Removal of Residual Metal Oxide after Cu-CMP in Ultra-Precision Machining

作　　者：顾张冰 牛新环[1,3] 刘玉岭[1,2] 高宝红[2] 王辰伟[2] 邓海文[1,2] 

机构地区：[1]河北工业大学电子信息工程学院,天津300401 [2]河北工业大学微电子技术与材料研究所,天津300130 [3]天津市电子材料与器件重点实验室,天津300401

出　　处：《稀有金属》2017年第2期146-154,共9页Chinese Journal of Rare Metals

基　　金：国家中长期科技发展规划02科技重大专项项目(2009ZX02308-003;2014ZX02301003-007);河北省自然科学基金项目(F201502267)资助

摘　　要：多层铜布线经过化学机械平坦化(CMP)后,铜线条表面会残留CuO颗粒,它会对器件的稳定性有很大的影响,因此在CMP后清洗时必须把CuO从铜表面去除。这就要求有一种可以有效去除铜表面CuO的清洗剂。本研究中提出的新型复合清洗剂主要解决两个问题:一个是CuO的去除,另一个是防止清洗液对铜表面造成腐蚀。清洗剂的主要成分有两种,一种是FA/OⅡ型碱性螯合剂,它主要用来去除CuO,另一种是FA/OI型表面活性剂,它主要用来解决铜表面的腐蚀问题。通过在铜光片的表面生成氧化铜膜层,利用清洗剂对氧化层的清洗能力来反映其对于CuO的去除能力。表面活性剂的抗腐蚀能力主要通过电化学实验来反映。最后通过对清洗后12英寸图形片上的缺陷分析,验证清洗液对抛光后铜表面残余CuO实际清洗效果。结果表明,本文提出的复合清洗剂在不腐蚀铜表面的前提下能有效去除CuO,并且对晶圆表面缺陷的整体去除效果良好。After conducting chemical mechanical planarization（CMP） on multilevel copper interconnection,CuO particles left on copper surface had a great influence on the stability and efficiency of integrated circuit.So an effective cleaning solution needed to be invented for removing CuO from the copper surface in the process of post CMP cleaning.In this work,a novel compound cleaning solution was proposed to solve two major problems.One was removing CuO and the other was copper surface corrosion caused by cleaning solution.The alkaline chelating agent（FA/O II type） used to remove CuO and the surfactant（FA/O I type） used as corrosion inhibitor were main compositions of cleaning solution.The capacity of removing CuO was characterized by the cleaning effect of copper oxide layer,which was generated on copper surface in advance.And the inhibiting corrosion ability of surfactant was characterized by electrochemical experiments.Finally,by analyzing the defects of 12 inch copper pattern wafer,the cleaning performance of different cleaning solutions was verified.Results indicated that the proposed compound cleaning solution had effective efficiency in removing CuO and other defects without corroding copper surface.

关 键 词：去除氧化铜 碱性清洗液 电化学 腐蚀抑制剂 

分 类 号：TN305.2[电子电信—物理电子学]