Experimental and modeling studies of particle removal in post silicon chemical mechanical planarization cleaning process

Experiments were carried out in order to evaluate the particle removal efficiency from a wafer surface by means of a buffing disk in a process for flow rates of chemical media ranging from 3.33 × 10−6 m3/s to 6.67 × 10− 6 m3/s, buffing disc pressures of 6.894 kPa to 20.684 kPa and three relative speeds were used in the experiments. A mathematical model which considered the toppling of a particle as a result of forces due to friction, hydrodynamic drag, adhesion and capillary phenomena was developed in order to correlate the particle removal efficiency with the flow rate, buffing disc pressure and relative rotational speed. Results of simulations of the model showed a good agreement with the experimental data with satisfactory correlation coefficients.