Site-specific self-assembly of Si/SiOx nanoparticles on micropatterned poly(dimethylsiloxane) thin films

Recent efforts have focused on the design of 20 and 3D assemblies with the goal of creating highly ordered supramolecular structures. Ultrathin films patterned with topologically different surface chemical functionality may b e used as a template for such elaborate architectures. Surface functionaliz ation can be used to impose site-specific assembly and can further lead to the fabrication of highly ordered structures, which have a great importance in the microelectronic and optoelectronic industry. Recently, we have demo nstrated the fabrication of surface modified Si/SiOx nanoparticles and thei r self-assembly on various surfaces. We presently report the specific self- assembly of Si/SiOx nanoparticles on poly(dimethylsiloxane) (PDMS) spin-cas t films. The desire to create regions of SiOx, which coexist with silicones in a two-dimensional film, is motivated by the difference in surface energ ies and affinity contrast between SiOx and PDMS. As presently reported, the selectivity of the deposition of Si/SiOx nanoparticles on PDMS versus UV/O -3 converted SiOx offers a gnat opportunity for the fabrication of periodic structures with large modulation in refractive index. (C) 2001 Published b y Elsevier Science B.V.