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Self-assembly is the autonomous organization of components into patterns or structures without human intervention. At the molecular level, self-assembly usually involves non-covalent interactions of various natures, such as van der Waals, electrostatic and hydrophobic interactions, hydrogen and coordination bonds. Thus, this process provides one solution to the fabrication of ordered aggregates from components with typical sizes in the submicron scale, which is a key to applications in nanotechnology. The work presented in this thesis aims at producing hybrid and functional nanostructured silicon surfaces using self-assembled metallic nanostructures. As self-assembling tool, we use polystyrene-block-poly(2-vinylpyridine) (PS-b-P2VP) copolymers, which are amph...
We report a pH-mediated synthetic route for the production of ordered and size-tuneable arrays of gold nanorings using responsive block copolymer micelles as templates.
We report a simple and versatile self-assembly method for controlling the placement of functional gold nanoparticles on silicon substrates using micellar templates. The hierarchical positioning of gold nanoparticles is achieved in one-step during the spontaneous phase inversion of spherical poly(styrene)block-poly(2-vinylpyridine) copolymer micelles into nanoring structures. The placement is mainly driven by the establishment of electrostatic interactions between the nanoparticle ligands and the pyridine groups exposed at the interface. In particular, we show the formation of ordered arrangements of single gold nanoparticles or nanoparticle clusters and demonstrate that their morphologies, densities and periodicities can be tuned by simply varying the initial block copolymer molecular weight or the deposition conditions. Besides gold n...
In this work, nanosphere lithography was integrated with standard microfabrication for the wafer-scale fabrication of silicon nitride (SiN) membranes with arrays of submicrometer holes. A monolayer of polystyrene (PS) beads with a mean diameter of 428 or 535 nm was spin coated onto the front side of a (100)-silicon wafer double-side coated with 100 nm of low-stress SiN. The size of the deposited PS beads was reduced by oxygen plasma reactive ion etching. This allowed to tune the hole size in the released SiN membrane while maintaining the hole array periodicity. Using the size-reduced PS beads as a lift-off template in a standard nanosphere lithography lift-off procedure, a 20 nm thick chromium hole etch mask was realized. This hole mask was patterned by UV photolithography, thus allowing for the local dry-etching of holes into the SiN...
We present the fabrication of thin membranes with dense arrays of nanometer and submicrometer pore arrays by the integration of standard micromachining with three pore patterning techniques: electron beam lithography (EBL), nanosphere lithography (NSL) and aluminum anodization. Using a serial top-down EBL technique we exploit a fine size, positioning and flexibility of this tool. NSL and aluminum anodization, as self-organized bottom-up processes, guaranties cost efficiency and throughput. In our work, we have fabricated silicon nitride (SiN) and alumina (Al2O3) membranes with a thickness down to 100 nm, side length ranging from 200 μm up to 2.4 mm and pore size ranging from 20 nm to 500 nm.
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