Electrochemically etched pore array in silicon with large spacing and high-aspect-ratio

Based on electrochemical etching with illumination from backside, we present a novel fabrication technique which can produce pore array in silicon with large pore spacing and high-aspect-ratio, and the regularly distributed pore array with both spacing and depth of up to several hundred micrometers can be achieved. The difficulties have been investigated according to the mechanism of macroporous silicon formation, and the primary design guidelines of the mask and the processing environment are given.