Researchers from KAIST and Pohang University of Science and Technology have studied inorganic nanopatterned arrays with a block copolymer template. Block copolymer can self-assemble ordered nanopatterns with a feature size of 5–50 nm. It is very suitable for ultrahigh-density nanodevice fabrication. The normal approach for patterning of inorganic nanostructures is usually based on selective etching. As an alternative, sol-gel chemistry combined with a block copolymer template demonstrates low-cost and large-scale production for nanodevice fabrication.

With the decreasing size of information storage devices, assembly of ultra high-density nanodot arrays will have promising applications. It is found that simple oxygen plasma can make a uniform porous polymer template (see left image). After a simple spin coating and thermal annealing process, a uniform ferromagnetic nanodot array (see right image) can be easily fabricated over a large area. It is also significant that a very high coercivity up to 10 kOe was obtained in a CoPt nanodot array.

This method can find attractive applications in the fabrication of ultrahigh-density storage media. Further experiments on other magnetic materials and optimal structures and properties are under way.

The researchers presented their results in the journal Nanotechnology.