Ordered nanostructures in semiconductors are a prime platform to study basic nanophotonics and have many applications as photonic crystals. In addition these structures can function as chemical sensors, devices to alter the wetting of liquids on a surface, and capacitors in high-frequency electronics used in mobile phones.
Therefore, COPS has developed a novel CMOS compatible method to fabricate arrays of many deep nanopores in silicon. We have defined the structures with the aid of advanced deep UV lithography in collaboration with ASML.
We optimized the plasma etching method that is also used in industry, to obtain very deep nanopores with world-record depth to diameter aspect ratios. We found that the novel structures behave as high-quality photonic crystals with broad forbidden bands in the telecommunication ranges near 1300 and 1550 nm, see Figures below.