CeNS Colloquium

Ricardo Ruiz
Hitachi Global Storage Technologies, San Jose Research Center

As the magnetic storage industry considers the introduction of patterned media technology as a route to thermally stable magnetic recording at densities beyond 1Tbit/in², innovation for alternative lithographic processes to achieve patterns with full pitch below 25nm is critical to enable suitable templates for patterned media. We anticipate that fabrication specifications will require a 1 5% for both critical dimension and placement accuracy making patterned media templates extremely challenging for any current lithographic technique. Directed assembly combines the uniformity of block copolymer self assembly with the long range placement accuracy of e-beam lithography as an alternative route to achieving dense patterns with tight size and placement tolerances. We start by defining a chemical contrast pattern on the substrate by e-beam lithography to direct the subsequent assembly of a block copolymer film. Directed assembly not only corrects noise and non-uniformities on the pre-pattern, but also multiplies the density of features by at least a factor of four. The feature density multiplication and pattern rectification demonstrated by directed assembly provide a method to enhance the capabilities of e-beam lithography enabling higher resolution with improved pattern quality and a reduction of writing time affording a path to master template fabrication in time for patterned media technology.