利用三维格子Boltzmann法研究化学机械抛光中压力分布

Hydrodynamic Pressure Distribution Simulation for Chemical Mechanical Polishing by Three-dimensional Lattice Boltzmann Method

利用三维格子Boltzmann法(LBM),对化学机械抛光(CMP)的润滑过程做了数值模拟,得到了不同晶片和抛光垫转速下的压力分布,并讨论了抛光液黏度对高压涡中压力最大值的影响。数值模拟结果表明,晶片自转是产生"双涡图"的主要原因,抛光垫旋转则主要产生"单涡图",抛光垫和晶片旋转的综合作用一起影响抛光效果,其中抛光垫的转速的改变对去除率影响较大。利用格子Boltzmann法模拟润滑问题,所得结果与求解Reynolds方程的结果一致,并具有计算效率高、几何直观等特性,能实现CMP过程的三维模型,且较容易实现对多相流的模拟。

A chemical mechanical polishing（CMP） lubrication process was numerically simulated with three dimensional lattice Boltzmann method, the pressure distribution under different rotating speeds of wafer and pad was obtained, and the effect of the viscosity of polishing fluid on the maximum magnitude of the pressure was discussed. The simulation results show that＇ double vortex zone＇ is generated by the rotation of the wafer, while the ‘single vortex zone＇ is mainly caused by the rotation of the pad. The polishing quality is affected by the combined motion of wafer and polishing pad, and the rotation of the pad plays a more important role in material removing rate. The results obtained by simulating the lubricative problems with LBM are consistent with those by solving Reynolds lubrication equation. The LBM has high calculation efficiency, which can realize the three-dimensional simulation of CMP process, and can be used to simulate the multi-phase fluid problem.