Lithographically directed deposition of silica nanoparticles using spin coating

Directed self-assembly is an important direction for the extension of patterning to the nanoscale regime and below. Here, examples are given of both individual particle placement and composite structure formation involving assemblies of many nanometer scale particles. both on patterned surfaces and on planar surfaces where the photoresist is used as a sacrificial layer to define the pattern and is subsequently removed. The underlying technologies employed in these experiments include interferometric lithography to define large-area, nanometer-scale patterns and directed self-assembly by spin coating, to control particle placement. Three sizes of silica nanoparticles (mean diameters: 78, 50, and 15 nm) were employed for spin-coating processes. Single linear silica particle chain patterns and isolated two-dimensional particle patterns were easily formed on patterned surfaces. Silica particle rows, cross networks, and isolated posts with controllable thickness could be formed on flat surfaces using this approach. Directed self-assembly using nanoscale lithography and spin coating is a facile approach to the extension of lithographic techniques to the nanoscale. (C) 2004 American Vacuum Society.