Three-dimensional colloidal crystal-assisted lithography for two-dimensional patterned arrays

In this paper, we report our recent work on preparing two-dimensional patterned microstructure arrays using three-dimensional colloidal crystals as templates, namely, colloidal crystal-assisted lithography. Two alternative processes are described and involved in colloidal crystal-assisted lithography. One is based upon imprinting the polymer films with three-dimensional silica colloidal crystals, and the other is based upon chemically depositing Ag microstructures on Au substrates covered by polymer colloidal crystals. By varying the experimental conditions in the colloidal crystal-assisted lithography process, we can intentionally control the morphologies of the resulting microstructures. The resultant Ag-coated Au substrates can be used as surface-enhanced Raman scattering substrates, and they would provide an ideal system for the mechanism study of surface-enhanced Raman scattering. We expect that colloidal crystal-assisted lithography will be a versatile approach which can be applied to patterning other materials such as functional molecules, polymers, oxides, and metals.