A Numerical Simulation of Motion of Particles under the Wafer in CMP

Motion of particles in two-phase flow between two rotary pads is simulated with coupled lattice Boltzmann method (LBM) and discrete element method (DEM), in which the LBM is used for calculating the fluid flow, while the DEM for accounting for the interaction between the moving particles, both the particles and the pads are constructed by the ´boundary´ in LBM. Numerically, flow field on the down-pad is simulated, two vortexes are found; Pressure maps are observed with different pad angle velocities; Finally motion of particles are investigated, our results show that most of the particles between the pads get out of the interlayer at nearly the same place, and the trajectory is like a parabola at the left hand side of the up-pad, all of them demonstrate the capability of the presented coupling strategy.