化学机械抛光中抛光垫作用分析

化学机械抛光（chemical mechanical polishing／planarization，CMP）能够提供高级别的整体平面度和局部平面度而成为集成电路（integrated circuit，IC）中起重要作用的一门技术．抛光垫是CMP性能的主要影响因素．这里建立了一个初步的二维流动模型以考虑抛光垫的弹性、孔隙参数、粗糙度以及晶片形状等因素对抛光液流动性能的影响，并通过数值模拟得出了它们对压力分布和膜厚等的作用．结果表明：由于抛光垫的变形和多孔性，承载能力将有所下降，膜厚增大，从而有利于抛光液中粒子和磨屑的带出．晶片表面曲率的变化对压力和膜厚的作用也很明显，全膜条件粗糙度的存在将引起流体压力的波动．研究为设计CMP中合适的抛光垫参数提供了初步的理论依据．

Analysis on Pad Effects in Chemical Mechanical Polishing

Currently,Chemical Mechanical Polishing/Planarization(CMP) is in the limelight of integrate circuit(IC) industries because of its ability to attain high level of global and local planarity required,which needs concentrated researches.Due to the fact that the knowledge on the mechanism is far from being promising,the further utilization is hampered.A preliminary wafer-scale flow model for CMP is presented in order to consider the effect of the wafer shape,the roughness,porosity and shape on the fluidity of the slurry.Numerical simulations were conducted to dig out the influences of these aforementioned parameters on pressure distribution and film thickness.Results show that the compressibility of the pad and the porosity contribute to a load deduction and an increase in film thickness,therefore,it can facilitate the delivering of the particles contained in the slurries and the debris.The alteration of wafer surface curvature plays a significant role in the pressure distribution.The pressure fluctuation is a prominent feature as far as the pad roughness is concerned.This research sheds some theoretical lights on the mechanism of the pad contributing to the CMP performances and paves the way for further applications of CMP technique.