圆平动化学机械研抛过程的流体动力性能分析

Hydrodynamic Analysis of Chemical Mechanical Polishing with Circular Translational Moving

根据圆平动化学机械研抛(C ircular-translational-moving Chem icalMechan ical Polishing,CTM-CMP)的运动关系,建立了极坐标下非稳态流体膜厚方程和非稳态下牛顿流体在CTM-CMP过程中的润滑方程。利用有限差分法数值求解获得了瞬时工件与研抛盘间的压力分布和膜厚分布,分析了压力积分载荷、倾覆力矩与研抛速率及姿态角的变化关系。结果表明CTM-CMP过程易于形成负压,有利于提高研磨效率。随着研抛速率的增加,承载能力和倾覆力矩线性增加;随着倾角的增加,承载能力和倾覆力矩非线性增大。分析结果有助于指导CTM-CMP的应用。

Based on the motion analysis of circular-translational-moving chemical mechanical polishing （CTM-CMP）, the fluid film equation and Reynolds equation of CTM-CMP in polar coordinates were set up under unstable state. These equations were calculated by using the finite difference method, and the instantaneous 3-D distributions of fluid pressure and film thickness between wafer and a rigid polishing pad were obtained. And the relations of the loading capacity and the resulted upsetting moments to linear polishing velocity and the rolling angle were analyzed respectively. Results show that negative pressure could be formed more easily in CTM-CMP process, facilitating the enhancement of polishing efficiency. The loading capacity and the value of upsetting moments increase with polishing velocity in a linear way ,and increase nonlinearly with upsetting angle. These hydrodynamic analyses may provide useful guidelines for the application of CTM - CMP process.