page_title: Local oxidation nanolithography
section_title: Molecular template growth and preferential deposition
hierarchical_section_title: Local oxidation nanolithography / Applications / Molecular template growth and preferential deposition
caption_attribution_description: English: Procedure for the patterning of Mn12 single molecule magnets using surface functionalizations and local oxidation naolithography.
context_page_description: Local oxidation nanolithography is a tip-based nanofabrication method. It is based on the spatial confinement on an oxidation reaction under the sharp tip of an atomic force microscope.
  The first materials on which LON was demonstrated were Si and polycrystalline tantalum. Subsequently, the technique has been extended to III–V semiconductors, silicon carbide, metals such as titanium, tantalum, aluminium, molybdenum, nickel and niobium; thin films of manganite in the perovskite form; dielectrics like silicon nitride, organosilane self-assembled monolayers, dendritic macromolecules and carbonaceous films.
context_section_description: Local oxidation of silicon surfaces by noncontact atomic-force microscopy is an emerging and promising method for patterning surfaces at the nanometer scale due to its very precise control of the feature size. The features created with this technique can be used for the template growth and preferential deposition of different molecules like single molecule magnets, biomolecules and conjugated organic molecules.
  This method of nanopositioning is an important tool for the fabrication of new nanodevices based on the novel properties exhibited by some nanoparticles and molecules. Potential applications of single-molecule magnets (SMMs) such as Mn12 as bits for information storage or qubits for quantum computation require methods for nanoscale-controlled positioning and/or manipulation of those molecules. The patterning of the Mn₁₂ molecules on a silicon surface is achieved by first derivatizing this surface with a self-assembled monolayer of APTES, which leaves it terminated by amino groups (-NH₂). Such termination electrostatically repels the Mn12 molecules. Subsequently, a pattern of silicon dioxide is defined by LON. The SMM molecules are predominantly deposited on the oxide motives because of electrostatic attraction.  The electrostatic attraction between the silicon oxide fabricated by LON and the Mn₁₂ molecules achieves the preferential deposition of this molecules with a nanoscale accuracy.
caption: Using specific functionalizations it is possible to deposit molecules and nanoparticles only in very small domains over a substrate surface. LON is a powerful technique to fabricate this kind of domains for the preferential growth.
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