FA/OⅡ型螯合剂对多层Cu布线CMP后BTA去除的研究∗

摘要

在化学机械抛光(CMP)过程中,加入苯并三氮唑(BTA)抑制 Cu 界面和布线条的腐蚀.但同时,会与Cu发生化学反应生成的Cu-BTA钝化膜是CMP后主要的清洗对象之一.采用FA/OⅡ型螯合剂作为清洗液的主要成分,采用接触角测试仪及原子力显微镜来表征BTA的去除效果.通过改变 FA/OⅡ型螯合剂的浓度完成一系列对比实验,确定最佳的清洗效果.通过对比实验得知,当清洗液中螯合剂的浓度为1．50×10－4~200×10－4时,此时清洗液的pH 值＞10,能有效去除Cu-BTA 钝化膜以及其它残留的有机物,接触角下降到29°,表面的粗糙度较低.%In the chemical mechanical polishing (CMP)process,benzotriazole (BTA)was used as corrosion in-hibitor in the copper CMP.The insoluble Cu-BTA passivation film was one of the main targets in post-CMP cleaning.FA/OII chelating agent was the main component of the cleaning liquid,which was used in this paper. Contact angle measurements and atomic force microscope was used to monitor the removal of BTA.By varying the concentration of chelating agent,a series of experiments were performed to determine the best cleaning re-sults.When the concentration of chelating agent between 1.50×10-4 and 2.00×10-4 ,the pH value was higher than 10,can effectively remove the Cu-BTA passivation film and other organic residue and the contact angle de-creased to 29°.The surface roughness was better.The proposed cleaning solution showed good ability in remo-ving BTA from the copper surface.