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Materials science and technology is fundamental to the majority of the applications of nanotechnology. 'Raw' materials such as semiconductors, oxides and specialist organic and inorganic chemicals, will need to meet new specifications and parameters. For example:
Nanoparticles: Controlled production of particles in the 1 - 100 nm size range is crucial, and handling of these fine particles will be a key issue.
Quantum structures: Material purity is of the highest importance here, and research into production methodology is required.
Multilayer thin films: These require clean deposition equipment and
environment (impurities and defects will ruin the properties of the films) with
fast turn-around and high throughput... Also, very high purity materials will be
needed for sputtering and evaporation sources.
Nanomechanical devices: The physical integrity of the material used to produce the devices will be of key importance, given the strains and stresses to which it will be subject.
Nanoprobe materials: These are the materials required for the
manufacture of tips for scanning probe microscopes, the basic tools of
nanotechnology. These need to be chemically inert, physically stable materials
capable of being fashioned reproducibly into atomic sharp tips.
Biosensors and transducers: The capability of synthesizing ultra high purity specialist organic chemicals having a range of terminating groups for these applications is required, as well as ways of bonding these molecules reproducibly to the surfaces of semiconductors and oxide materials.
Advanced manufacturing processes: Manufacturing processes at the nanoscale can involve accretion or removal of material, or changes to the shape or form of material already present. Each of these processes provides new challenges and opportunities, as follows:
Accretion of powders: New generations of processing equipment will be needed to deal with nanopowders in the manufacture of nanocrystalline materials.
Quantum structures and devices: The problem of producing devices with critical dimensions below 100nm, using 'top-down' techniques, is one that the electronics industry is currently wrestling with. Currently, commercial lithography is based on optical methods, 10 Current and Emerging Electronic And Computer Technologies but the wavelengths of visible and near ultraviolet light are too long to be usable on the nanometer scale. A range of alternatives is available, but parallel rather than serial writing techniques are needed for scale-up to commercial manufacturing levels.
Deposition: Recent breakthroughs are making deposition on selected areas possible, in high transmission mode. Until now, this has been achieved only through focused ion beam sources operated in droplet mode - an approach which is restrictive in terms of the range of materials that can be handled.
Cutting, milling: Only focused ion beam (FIB) techniques provide a
means for selective cutting or removal of material with sub-100nm accuracy.
Although these techniques were largely pioneered in Europe - and the UK in
particular - the present suppliers of such equipment are almost exclusively
American or Japanese companies. |
