碱性条件下铝CMP的机理分析及实验优化  

Mechanism Analysis and Experimental Optimization of Al CMP Under Alkaline Condition

作　　者：韩丽丽[1] 刘玉岭[1] 牛新环[1] 

机构地区：[1]河北工业大学微电子研究所,天津300130

出　　处：《微纳电子技术》2012年第4期280-284,共5页Micronanoelectronic Technology

基　　金：国家中长期科技发展规划02科技重大专项(2009ZX02308)

摘　　要：依据铝的电化学腐蚀特性,阐明了碱性条件下铝化学机械抛光(CMP)的机理。由于铝的硬度较低,在抛光过程中容易产生微划伤等缺陷,因此首先探索出适宜铝化学机械抛光的低压条件(4 psi,1 psi=6.895 kPa)。此外,提出两步抛光的方法,在抛光初期采用压力4 psi,抛光液由质量分数为40%的纳米级硅溶胶与去离子水(DIW)以体积比1∶1配制,氧化剂(H2O2)体积分数为1.5%,FA/O I型表面活性剂体积分数为1%,调节FA/OⅡ型螯合剂pH值为11.0,获得了较高的铝去除速率(341 nm/min)。在抛光后期采用低压1.45 psi,抛光液主要成分为体积分数5%的FA/O表面活性剂,并在较大体积流量(300 mL/min)的条件下进行抛光,充分利用表面活性剂的作用,对实验方案进行优化。采用优化后的实验方案,铝表面的划伤和缺陷显著减少。According to the electrochemical corrosion characteristics of aluminum,the mechanism of chemical mechanical polishing（CMP） under alkaline condition was analyzed.Aluminum has low hardness,and it is easy to generate micro-scratches and other defects in polishing.So the appropriate low pressure condition（4 psi,1 psi=6.895 kPa） for aluminum CMP was explored firstly.In addition,the method of two steps polis-hing was proposed.In the early period of poli-shing,when the pressure is 4 psi,the polishing slurry consists of silica sol（the mass fraction of which is 40% and abrasive size is nm level） and deionized water（DIW） with the volume ratio of 1∶1.Besides that,the volume ratio of the oxidant（H2O2） is 1.5%,the volume ratio of FA/O I-type surfactant is 1%,the pH value adjusted by FA/O II-type chelating agent is 11.0.Then,higher aluminum removal rate（341 nm/min） was acquired.In the later polishing period,with lower pressure 1.45 psi,the main composition of the slurry is FA/O surfactant with the volume ratio of 5%,and the polishing volume flow is large（300 mL/min）.The experimental program was optimized with the surfactant fully utilized.After applying the optimization scheme,the defects and scratches at the surface of aluminum are reduced significantly.

关 键 词：铝(Al) 化学机械抛光(CMP) 抛光液 去除速率 表面活性剂 

分 类 号：TN305.2[电子电信—物理电子学] TG146.21[一般工业技术—材料科学与工程]