METHOD AND APPARATUS FOR RADIATION-ASSISTED ELECTROCHEMICAL ETCHING AND ETCHED PRODUCT

摘要

The light irradiation type electrochemical etching apparatus 10 includes an etching bath 12 for holding one surface 32 of the n-type silicon substrate 20 in contact with the hydrofluoric acid solution 14, A power source 30 having an anode and a cathode and having an anode connected to the silicon substrate and a cathode connected to the electrode and a light source 56 for illuminating the other surface 38 of the silicon substrate And an illumination unit 52 having a plurality of illumination units. Then, the illumination section illuminates the other surface of the silicon substrate at an illuminance of 10 mW / cm or more. And the ratio of the maximum roughness to the minimum roughness of the other surface of the silicon substrate is set to 1.69 or less. According to this etching apparatus, even for a silicon substrate having a diameter of 3 inches or more, pores and trenches of any size and shape can be formed on the entire silicon substrate.