The Synthesis’ researchers’ knowhow and instrumental facilities available at ISM offer different treatments such as micro and nanostructuring and creation of microchannels and color centers of materials whose are located onto the surface or inside the material, respectively.
The Surface nanostructures obtained on large band gap systems, such as diamond films, have allowed: 1) the modulation of optical properties (e.g. blackdiamond) which have enhanced the absorption of solar radiation used in conversion modules of solar concentrators based on new generation thermionic and thermoelectric technologies, or, 2) the creation of metamaterials obtained as a result of surface graphitization that find application for THz spectral range components. Different treatment processes can be carried out by the use of a micro and nanofabrication workstation µFAB, managed jointly by the DiaTHEMA Lab and Tito Scalo FemtoLab, whose coupling with a Ti:Sa fs laser source, can provide micro and nanometric scale fabrications (micromachining, and internal micro and nanostructuring of materials’ surfaces, etc.). These, as a consequence of their high 1D, 2D or 3D achievable periodicity, can allow the manipulation and control of materials’ optical, electronic, charge transport and electromagnetic radiation – matter interaction, reactivity or more generally chemical-physical properties and therefore their peculiar behaviors (e.g. creation of color centers of high band gap systems, variation of refractive indices and/or surface wettability of materials etc.). In general, due to local features that can be designed and realized at the nanoscale, innovative technological systems that find application in areas such as: photonics, microfluidics, micro and nanoelectronics, optoelectronics, optimization in processes chain such as painting of aesthetic polymeric systems used in the automotive industry, can be obtained.

2D-3D microfabrications by a fs pulsed laser coupled to a uFAB workstation

Together with the production of thin films and heterostructures, the Synthesis units offers the opportunity of depositing thin films by the Chemical Vapour Deposition – CVD technique.
Since last decade or so ISM has enhanced a state-of-the-art knowhow for the formation and growth of carbon-based materials such as synthetic diamond, amorphous carbon, Diamond-Like Carbon (DLC), nanotubes and graphene, in the form of thin layers suitable for electronic, optical, mechanical, thermal and optoelectronic applications.
At the DiaTHEMA Lab at ISM Montelibretti branch, thin carbon-based layers are deposited using CVD such as the MicroWave-Enhanced (MW-CVD) and the Hot-Filament CVD (HF-CVD) together with the employment of gaseous mixtures of hydrogen, methane, argon and / or nitrogen.
Diamond layers, in particular, are the main topic research which regards their production and optimization in the form of polycrystalline or nanocrystalline deposits performed onto silicon substrate surfaces, as well as carbides and nitrides deposited either over large areas (heteroepitaxy) or monocrystalline onto HPHT (high pressure high temperature) diamond substrates or CVD synthetic ones.
With regard to MW-CVD technique it differs from HF-CVD one in the control of the process, which gives advantages for the growth of a material having a low concentration of defects and impurities which suitable for either electronic devices or for the detection of ionizing radiations. The advantage of the HF-CVD technique is, on the contrary, related to its ability in providing, over large areas, uniform deposition of diamond layers. The applications carbon-based layers obtained by CVD span from the coating of cutting tools to heat dissipation, from radiation detection to power electronics, from nuclear to solar energy conversion and from optoelectronics to quantum computers.

Microwave enhanced CVD Hot-filament CVD

Since the late 1980s, ISM has developed activities and skills regarding the deposition and growth for Physical Vapor Deposition of superconducting, semiconductor, magnetic, and ceramic thin films that are of interest for electronics, sensors, optoelectronics, data storage, ICT and biomedicine applications.
The techniques used range from thermal evaporation and RF-Sputtering to Laser Ablation and Deposition (Pulsed Laser Deposition - PLD). Thanks to the numerous laser sources available and the consolidated experiences acquired over the years by the ISM researchers, PLD represents a technique that can be used in different operating conditions, regulated by both the wavelength of the laser beam and the duration of its pulse as well as by the surrounding environment, that is the presence of: a background gas, a reactive atmosphere or high vacuum. For instance, this technique, whose laser-matter interaction processes and, for sufficiently long pulses (e.g. ns) also those interactions occurring between the laser induced plasma and the laser itself, are strongly dependent on the laser parameters used. The process is based on the "vaporization", in the form of plasma and even nanoparticles when ultrashort pulses, that is in the range of tens of fs are used. PLD can be applied to any inorganic, organic or biological material (e.g. oxides, carbides, nitrides, metals, alloys, polymers, biological materials, etc.) whose subsequent deposition on a support (substrate) is characterized by a complex control of the stoichiometric ratios and properties and dynamics of the various species involved making the laser source parameters and experimental conditions used the key factors for the deposited materials’ features. It follows that the deposition onto the surface of suitable and properly chosen substrates of the vaporized species provide the growth of innovative thin films, or new nanostructured materials. These can be obtained in either as a single or multilayer form or also, when in combination with other techniques such as RF-Sputtering, in order to deposit heterostructure that are otherwise difficult to be grown. ISM has five laboratories employing state-of-the-art PLD which are located at both its Roman branches of Tor Vergata and Montelibretti and at the Southern Italy branch of Tito Scalo (PZ). Because of the different experimental configurations available, the PLD typology to be employed can be chosen on both the laser source features (e.g. pulse duration: 120fs - 30ns, and wavelengths which spans from UV to NIR spectrum interval) or even in case other co-deposition systems or in-situ treatments are required (i.e. occurrind in the same deposition and growth chamber where the thin films or nanostructured materials under study are generated).  To complete the variety of the PVD technique features offered, an electron beam evaporation system, valuable for the development of ultra-thin layers of fluorides, nitrides, carbides and borides, it is also available.

ns-PLD (@532 nm) ns-PLD (@193 nm) ns-PLD (@248 nm) ns-PLD (@1064-532-355-266 nm) Electron beam evaporator fs-PLD (@800-400 nm) Leybold-Heraeus Low Vacuum Evaporator