Acceleration of groove formation in silicon using catalytic wire electrodes for development of a slicing technique

摘要

A novel electrochemical technique for silicon slicing in which anodic potential is applied to a platinum wire, keeping it in contact with silicon, is proposed. Since silicon was dissolved in a solution containing hydrogen fluoride at the site of contact with the platinum wire electrode, a groove was formed in the silicon. The grooving speed depended on the concentration of hydrogen fluoride and additives in the solution. A grooving speed of 0.85 mm/h was obtained at room temperature using an electrolyte composed of 30wt.% hydrofluoric acid, 1 mM iodine, and 0.03 vol.% glycerol. Iodine acted as a catalyst for the oxidaton of silicon, and glycerol prevented the filling of grooves with gases. Further increase in grooving speed to 1.0 mm/h was achieved by applying pulsed potentials oscillating between 1 and 2 V vs. Ag/AgCl in the same electrolyte.