Surface Finish Enhancement of Si(100) with Single Pole Magnetic Abrasive Finishing using Chemical Oxidizers and Alumina Slurry

The study aims to improve the surface finish of monocrystalline silicon wafer Si (100) with single-pole magnetic abrasive finishing along with slurry of alumina (1200 mesh) and chemical oxidizers (mixture of Marshall’s acid salt (K₂S₂O_8, 1.5%wt/wt), Caro’s acid salt (KSHO_5, 1.5%wt/wt), Sodium Hydroxide (NaOH, 1.5%wt/wt) and Hydrogen peroxide (H₂O_2, 0.5%wt/wt). The alumina slurry mixed with oxidizer flowed in the working-gap (the gap between the polishing tool and workpiece Si wafer) ranging between 6 to 8 mm. The process of polishing was conducted under different sets of conditions using three parameters, i.e., polishing-speed (X₁), working-gap (X₂) and workpiece feed-rate (X₃). With Response Surface Methodology (RSM) using the above-mentioned parameters, 20 sets of experiments were conducted and two responses i.e., surface roughness (R_a) and work brush temperature (WBT) variation were recorded during the process. The obtained data was examined using Analysis of Variance (ANOVA) and the optimum process parameters of surface roughness and work-brush temperature were determined. A statistical model was created for surface roughness and work brush temperature in terms of the process parameters. After eliminating non-significant terms, the Genetic Algorithm (GA) toolkit, which is a component of the MATLAB 13 package, was employed to optimize the model. The theoretical results were validated through a confirmation experiment conducted under optimal conditions. The study also investigated the surface morphology of unpolished samples and polished samples obtained at optimal parameters with the help of images from AFM and SEM. The chemically assisted process for finishing silicon wafer improved the finishing efficacy to 1.076, nanometers suitable for silicon and other such materials for industrial applications.