Large-Scale Fabrication of Periodic Nanostructured Materials by

Langmuir 2006, 22, 3955-3958

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Large-Scale Fabrication of Periodic Nanostructured Materials by Using Hexagonal Non-Close-Packed Colloidal Crystals as Templates Peng Jiang* Science and Technology DiVision, Corning Incorporated, Corning, New York 14831 ReceiVed August 25, 2005. In Final Form: March 9, 2006 This letter reports a versatile nonlithographic technique for mass fabricating three types of technologically important materialsspolymer microwell arrays, 2D-ordered magnetic nanodots, and semiconductor nanopillar arrays, each with high crystalline qualities and wafer-scale sizes. Spin-coated hexagonal non-close-packed silica colloidal crystals embedded in a polymer matrix are used as starting templates to create 2D polymeric microwell arrays. These throughhole arrays can then be used as second-generation templates to make periodic magnetic nanodots and semiconductor nanopillars. This self-assembly approach is compatible with standard semiconductor microfabrication, and complex micropatterns can be created for potential device applications. The wafer-scale technique may find important applications in biomicroanalysis, high-density magnetic recording media, and microphotonics.

Large-area-ordered nanostructured materials with periodicity ranging from the nanometer to submicrometer scale are widely used in various technological applications. For example, picoliter microwell arrays allow for the handling and isolation of very small volumes of liquid or single cells and are important in the miniaturization of analytical and bioanalytical techniques.1-4 Well-ordered arrays of metallic nanodots find potential applications in high-density magnetic data storage5,6 and biosensors,7,8 as well as templates for the growth of large arrays of aligned carbon nanotubes9 and ZnO nanorods10 that have been broadly explored in fabricating field-emission displays11 and ultraviolet nanolasers.12 Semiconductor nanopillar arrays have considerable utility in the separation of long DNA molecules,13 2D photonic crystals,14 and interferometric biosensors.15 To fabricate such nanostructures, photolithography (PL, for features >300 nm), electron beam lithography (EBL), and focused ion beam lithography (FIBL, for features