The use of potassium peroxidisulphate and Oxone® as oxidizers for the chemical mechanical polishing of silicon wafers

This communication deals with the chemical effect of oxidizer concentration and pH-value on the Material Removal Rate in Chemical Mechanical Polishing of silicon wafers. The lapping process is necessary to reduce the initial elevated roughness in as-cut samples. An optimal lapping applied pressure of 27 kPa was selected to be used with the optimal abrasive particle size of Al2O3 3 µm. Then, polishing process is carried out to obtain a well finished surface. Two abrasives were used, Al2O3 and CeO2(ceria), but only ceria slurry was chosen due to the resulting lower MRR value. The CMP was carried out in alkaline slurry using ceria particles with Oxone® and K2S2O8 as oxidizers, using H2O2 as a reference. The interaction between ceria particles and silicate ions was studied in order to further understand the CMP mechanism of silicon samples using ceria slurry and oxidizer. The results indicate that the use of an oxidizer improves the polishing quality resulting in a lower roughness and MRR value.