Chemical mechanical planarization (CMP) has the capability to achieve adequate local and global planarization for future submicrometer VLSI requirements [1]. It is known that the presence of both abrasive particles and chemicals is necessary to produce a desirable polish rate [2]. Material removal from the wafer surface is contributed by the combined action of abrasive particles and the chemical reagents in addition to the asperity contact. The fundamental physical and chemical mechanisms of CMP are not well understood. Modeling efforts are mostly attributed to Preston's equation while is from simple to more complex treatment of pad asperity, deformation, and bending [2]. Until recently, the modeling of the effects of the slurry flow and chemical reactions are included and presented in few published works [3-6]. The importance role of particles during the material removal process is treated more empirically in the most modeling efforts. The actual physical contributions for the abrasive particles in CMP material removal mechanism is not observed experimentally, and very limited in computational works. In the previous investigation [7], the role of abrasive particle for material removal is numerically observed and studied for CMP process. Two different pad geometries with groove are numerically investigated for particulate flow in wafer-pad slurry film. These two cases conclude that the particle impacts are rely on the particle resided on the wafer surface. These particles nearly follow the flow, and no particle impact has found even in the pad-groove region. Although a small turbulence is found in the slurry flow, the importance of turbulence effect on the particles is not fully studied in this investigation. In addition, the multiphase flow computations show the particle weight fraction is nearly uniform in the slurry flow. A further investigation [8] to study the role of turbulence effect on particle transportation and on material removal in CMP process is numerically observed and studied. Two-dimensional Newtonian turbulent viscous slurry flow in a groove and bumped wafer-pad passage is numerically computed in this investigation. The abrasive particles are modeled using Euler-Lagrange dispersed model with the inclusion of particle turbulent dispersion model to investigate the turbulence effect on the particle movement. The results show these particles can impact the wafer surface under the effect of turbulence on particle transportation, and the impact momentum can contribute the planarization process. The shear stresses distribution on the wafer surface shows the rough pad do increase the gradient of shear stresses and the shallow channel do receive a larger shear stress level in the planarization process. The groove can increase the impact frequency of particle with diameter less than 0.1 μm. This investigation indicates how the groove and rough pad surface can mechanically contribute the planarization process. In the present investigation, the role of groove effect on the particle transportation and on the material removal in CMP process is conducted numerically for a wafer-pad-groove and a wafer-pad geometries as shown in Figure 1 and 2. The role of turbulence effect on the particle transportation is numerically simulated in the above geometries to study the role of groove effect on the material removal in CMP process. The simulation principle for abrasive particle trajectories, impact, and erosion in viscous fluids is developed based on Hamed et.al.[9]. Two-dimensional Newtonian turbulent viscous slurry flow in the bumped wafer-pad passage with and without groove is studied in the present investigation. The abrasive particles are modeled using Euler-Lagrange dispersed model with the inclusion of particle turbulent dispersion model to investigate the particle movement in these two geometries. Simulations are modeled based on actual experimental observation with averaged pad-wafer channel depth of 50 μm in sine-waves bum
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