铜互连CMP中BTA的缓蚀机理及Cu-BTA的去除研究进展

Research Progress on Corrosion Inhibition Mechanism of BTA in Copper Interconnection CMP and Removal of Cu-BTA

铜具有低电阻率和高抗电迁移性,是目前极大规模集成电路的主流金属互连材料。化学机械抛光(CMP)是实现铜表面局部与全局平坦的关键工艺。为获得铜互连较高的凹凸材料去除速率选择比,通常需在CMP抛光液中加入缓蚀剂苯并三唑(BTA),而CMP后铜表面的BTA残留需要在后续的清洗工艺中进行有效的去除。对铜互连CMP中BTA对铜的腐蚀抑制机理的研究进行了归纳分析,并对BTA与其他试剂协同抑制铜腐蚀的研究进行了讨论,进而论述了碱性清洗液对Cu-BTA络合物去除的研究进展,并概述了新型缓蚀剂的研究现状,最后对缓蚀剂未来的研究方向进行了展望。

Because of its low resistivity and high resistivity to electromigration,copper has become the mainstream metal interconnection material for large scale integrated circuits.Chemical mechanical polishing(CMP)is a key technology to achieve local planarization and overall planarization of copper surface.In order to obtain higher removal rate selectivity of concave and convex materials for copper interconnection,the corrosion inhibitor benzotriazole(BTA)is usually added to CMP slurry,and the BTA residue on the copper surface after CMP needs to be effectively removed in subsequent cleaning process.The researches of copper corrosion inhibition mechanism by the BTA in copper interconnection CMP are summarized and analyzed.The researches for synergistic inhibition of copper corrosion by the BTA and other reagents are also discussed.Furthermore,the research progress of removal of Cu-BTA complex by alkaline cleaning solution is discussed.The research status of new corrosion inhibitors is overviewed.Finally,the future research directions of corrosion inhibitors are prospected.