This installation offers state-of-the-art tools from nine different and complementary nanoscience laboratories for nanomaterials growth & synthesis, including growth of thin films, multilayers and nanostructures and the preparation of nanostructured materials and soft matter using a variety of chemical approaches. Available growth techniques include Physical Vapour Deposition (PVD) in the form of Pulsed Laser Deposition (PLD) or Molecular Beam Epitaxy (MBE) adapted to grow oxides and semiconductors. Chemical Solution Deposition (CSD, including Ink Jet Printing), Atomic Layer Deposition (ALD) and Chemical Vapor Deposition (CVD) can be used for the growth of inorganic (oxides, nitrides), molecular, hybrid and biological materials, particularly in the form of thin films, nanostructures, self-assembled monolayers, liposomes, etc. Bio-nano facilities are also provided for the fabrication of cellular substrates and scaffolds. The available tools can be used to prepare a wide spectrum of nanomaterials in combination with the Lithography & Patterning and Characterization Installations.
CSD is a growth technique of thin films, self-assembled nanomaterials or nanocomposite thin films where chemical solution is first deposited on substrates and later on, through selected thermal processes, chemical precursors are transformed into solid compounds. A wide range of functional oxides and inorganic compounds are grown by CSD leading to epitaxial or polycrystalline structures and used as low cost and easily scalable approach to devices for many applications.
MBE allows growth of high quality semiconductors, oxides and organic epitaxial layers, with crystal structure commensurate with the substrate. It is used to build nanostructures (quantum dots, nanowires), layered heterostructures for lasers, photodetectors, LED and optoelectronic devices.
The CBE technique uses exclusively metal organic precursors in the growth process, hence the original name Metal Organic Molecular Beam Epitaxy, MOMBE. The choice of sources requires a vent/run injection system and results in a higher gas load and growth pressure, typically, in the low 10-5 mbar range, as opposed to 10-7 mbar or lower for the Molecular Beam Epitaxy. The higher pressure has the advantage of an increased growth rate, the CBE gives 0.8 ML/s for GaAs growth, corresponding to 0.8 µm/hr.
ALD has raised huge interest as advanced thin film manufacturing process for a wide variety of mainstream applications expanding beyond semiconductor processing. It includes achieving new levels of performance in Li-ion batteries, fuel cells, logic and memory devices, light-harvesting energy (i.e. surface passivation layers, buffer layers in solar cells) but also encapsulation of polymers.
The aerosol deposition process allows controllable size generation and deposition of aerosol particles of metals, e.g. Au, Ag, In, Pb, Pd, Cu. The size range of the aerosol particles is 8 - 100 nm with a narrow distribution. Aerosols can be randomly deposited on any substrate with densities up to 50 µm-2.
In CBD, aggregates formed in the gas-phase are processed in a molecular beam source so to form a collimated beam of particles that once intercepted by a substrate can be used to grow thin films of nanostructured materials. Nanocomposites are produced by co-deposition from multiple sources. Accessible materials are metals, carbon, metal-oxides.
FSP allows the production of a broad range of nanostructured materials in the form of nanocrystalline powders with particle sizes ranging from few nanometers up to 10 nm. These materials include metal oxides (e.g. SiO2, TiO2 and Al2O3), complex oxides (e.g. YSZ and ITO), noble metals and nanocomposites (e.g. alumina or titania supported Pt).
Processes involving exposure of (usually) semiconductors samples to oxidizing or inert ambient at high temperature (300- 1150C). For example, O2 or H2O ambient are used to grow silicon dioxide on Si. Inert ambient (N2, Ar) are used to densify layers or to activate and redistribute dopant impurities. N2/H2 is used for aluminum sintering. Thermal processes including an in-situ phosphorus predeposition from POCl3 or Boron predeposition from BN/B2O3 can be used for doping silicon.