ULSI硅衬底的化学机械抛光

Chemic-Mechanical Polishing of Silicon Wafer in ULSI

在分析 UL SI中硅衬底 CMP的动力学过程基础上 ,提出了在机械研磨去除产物过程中 ,适当增强化学作用可显著改善产物的质量传输过程 ,从而提高抛光效率 .在对不同粒径分散度的硅溶胶抛光液进行比较后提出了参与机械研磨的有效粒子数才是机械研磨过程的重要因素 ,而不是单纯受粒径大小的影响 .分析和讨论了 CMP工艺中的几个影响因素 ,如粒径大小与分散度、p H值、温度、流量和浓度等 .采用含表面活性剂和螯合剂的清洗液进行抛光后清洗 ,表面颗粒数优于国际 SEMI标准 。

The dynamical process of CMP used in silicon substrate in ULSI is analyzed,and a new viewpoint is put forward.Enhancing chemical effect may accelerate the mass transmitting process of output in the second step of CMP process,in which the output is mainly removed by mechanical abrading of slurry,and thus improve the removal rate.Many facts influencing CMP process are discussed,which mainly include particle size and dispersity, pH value,temperature,flow,and concentration of slurry etc.The different polishing slurry with different particle size dispersity are compared,and results show that the important fact influencing mechanical abrading is the number of effective particle,which really participate in mechanical abrading under certain conditions,not only particle size.After adding surfactant and chelant agent in slurry,polishing surface becomes better,the number of surface particle is better than that of the SEMI standard,and polishing haze is also effectively controlled.