Formation of 300 nm period pore arrays by laser interference lithography and electrochemical etching

International audienceThis paper highlights that combining laser interference lithography and electrochemical etching is a cost-effective, efficient method to realize periodic nanopore arrays in silicon with lattice pitch as small as 300 nm on centimeter-scale substrates. The fabrication of wide-area and high aspect ratio 2D pore arrays with 250 nm diameter and 5 mu m depth is demonstrated. All the steps of the process have been optimized to achieve vertical sidewalls with 50 nm thickness, providing pore arrays with aspect ratio of 100 on n-type silicon substrates over an area of 2 x 2 cm(2). These results constitute a technological advance in the realization of ordered pore arrays in silicon with very small lattice parameters, with impact in biotechnology, energy harvesting, or sensors. (C) 2015 AIP Publishing LLC