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

摘要

An electrochemical etching system (10) has an etching bath (12) for holding an n-type silicon substrate (20) with one surface (32) of the substrate being in contact with hydrofluoricacid (14), an electrode (28) positioned in hydrofluoricacid, a power source (30) having a positive polarity connected to the silicon substrate and a negative polarity connected to the electrode, and an illumination unit (52) having a light source (56) for an illumination of the other surface (38) of the silicon substrate. The illumination unit illuminates the other surface of the silicon substrate with an illumination of 10mW/cm<2> or more. Also, a ratio of a maximum illumination to a minimum illumination to the other surface of the silicon substrate is set 1.69:1 or less. With the etching system, pores and/or trenches of a certain size and shape can be formed in an entire area of the silicon substrate with a diameter of more than three inches. <IMAGE>