Effect of pad’s surface deformation and oscillation on monocrystalline silicon wafer surface quality

The silicon wafer polishing process has sensitive machining requirements owing to the interaction between various complex process factors, which can include the pad, slurry, applied pressure, polishing speed, polishing time, dressing condition, and the machining temperature. Among these important machining factors, applied pressure, polishing speed, and polishing time were examined. The optimum condition of wafer final polishing was investigated using the Taguchi approach. Moreover, variations in oscillation speed were added to the experiment and it was found that changing the surface contact velocity helped to improve the surface quality of the wafer. Furthermore, the pad surface characteristics which influences wafer surface quality after wafer final polishing with and without oscillation were studied and adding an oscillation speed in wafer final polishing has the dual benefit of improving wafer surface quality and reducing consumable costs. Finally, by selecting the optimum condition, it could achieve an ultra-precision wafer surface with almost no defects.