Wafer-scale directed self-assembly of nanostructures using self-assembled monolayer based controlled-wetting

Controlled spatial placement of nanostructure (NS) at micro/nano scale has attracted much attention since the last decade due to their applications in NS based device fabrication. Different processes like, chemical interaction based to solvent driven patterned assembly of NS have been reported. This work is about the large scale patterned assembly of different NS; cobalt and diamond nano particles and ZnO nanorods at micro/nano scale by controlling the surface wetting properties. Wettable and non-wettable patterned regions were created on gold/silicon surface using patterns of self-assembled monolayer (SAM). Patterns of SAMs with terminal end of CH3 were used to create non-wettable regions on wettable gold/silicon surfaces. Micro-contact printing, e-beam lithography, and simple scratch techniques were used to create SAM patterns of different shapes and sizes. Dipping the SAM patterned surface in the NS solution or by putting a droplet of the NS solution on the patterned surface the NS assembled according to SAM patterns only in the wettable, Au/silicon regions. I observed that wettability behavior of the surface plays a dominant role in the NS assembly in comparison to van der Waals’ and other interactions between surface and the NS.