Thin Me-DLC films with different metal contents have been deposited by ECR-CVD (Electron Cyclotron Resonance Chemical Vapour Deposition). Before the growth process, metal nanoparticles were scattered over the substrate surface by dipping it into a dispersion previously sonicated. The concentration of the dispersion (150, 300, 500 and 5000 ppm) controls the metal content into the carbon coating. The morphology of the deposited samples was analysed by SEM (Scanning Electron Microscopy). The metal content in the carbon films has been evaluated by SIMS (Secondary Ion Mass Spectroscopy). The incorporation of low amounts of metal nanoparticles into the hard carbon coating produces an outstanding improvement in the durability of the layer, as detected by pin-on-disc tests. For an optimum chromium content of 300 ppm of nanoparticles in the dispersion, the grown layer exhibits a noteworthy higher wear resistance respect to that of the DLC reference film. More precisely, in this case, the Cr-DLC coating undergoes ten times longer wear process than the reference DLC coating. However, it is important to indicate that in samples grown using more concentrated dispersions (> 300 ppm), a rapid deterioration of the coating is produced and short lifetimes have been detected, attributed to the large contribution of metal to the transfer layer.

CNT arrays were synthesized by Chemical Vapor Deposition (CVD) and spun into ribbons, which were coated using Atmospheric Pressure Microwave Plasma system. Time-of-Flight Secondary Ion Mass Spectrometry (TOF-SIMS) characterization of CNT ribbons indicated the presence of polymer films with CF2 as a repeat unit. Atomic concentration of C, F and O in the coated films was estimated from X-ray Photoelectron Spectroscopy (XPS) data. Types of bonding between the elements in the coated films was studied by curve fitting of C 1s XPS spectra.

Laser interference patterning-induced microstructural modifications have been investigated in two noble metal-incorporated oxide thin film systems: Pd0.25Pt0.75Ox and gold-incorporated yttria-stabilized zirconia - Au-YSZ. Transmission electron microscopy was used to investigate the influence of the laser treatment on the microstructure of the samples. In the case of Pd0.25Pt0.75Ox, the formation of a nanocomposite arrangement resulted from the precipitation of metal nanograins in the oxide matrix triggered by laser irradiation. In Au-YSZ, the starting microstructure consisted of gold nanograins embedded in a YSZ matrix. A noticeable growth and coalescence of gold nanograins occurred near the surface in the region of maximum interference. Simultaneously, a foamy morphology, mostly consisting of gold crystals, was formed at the film surface. In contrast to thermal annealing, the laser treatment proposed here is a fast procedure to partially relocate gold at the film surface and provide a local solid lubrication.

Statistical studies involving the fracture behavior of coatings can play an important role in the mechanical analysis of films employed in the hard coating industry. In this study, Nanoimpact tests using a cube corner indenter were carried out in various CrAl(Si)N coatings for the quantitative assessment of properties of coatings like non-catastropic failure time and catastrophic failure time. These parameters decrease in value as silicon is incorporated in coatings, showing that this addition results in a decrease in ductility. Scanning electron microscope images were taken to the analyzed coatings exhibiting the residual imprints after nanoimpact test that were correlated with the fracture behavior of CrAl(Si)N coatings.

We demonstrate the possibilities of plasma enhanced chemical vapor deposition (PECVD) and solid phase epitaxy to obtain germanium on silicon with excellent crystalline properties, even for very thin layers (< 100 nm). Amorphous germanium layers are deposited by PECVD on silicon substrates. Deposition of an amorphous layer, without the presence of crystalline seeds, is critical. Crystalline inclusions must be avoided to obtain high crystal quality and a smooth surface after crystallization. PECVD is well suited for deposition of amorphous layers because low temperature deposition and high growth rates are possible. Additional experiments with molecular beam epitaxy show that it is not mandatory to have hydrogen present inside the germanium layer to obtain highly crystalline germanium. Atomic hydrogen plays, however, an important role during deposition by lowering the surface adatom mobility and consequently increasing the disorder of the deposited layer. Synchrotron X-ray diffraction shows no germanium diffraction, indicating that the layer does not contain crystalline seeds. Crystallization can be performed at limited temperatures: Raman measurements show crystallization between 400 and 425 °C. Another important advantage of the proposed method is the scalability: germanium layers of larger diameter can be obtained by simply using larger silicon substrates.

A study is presented on nanocrystalline diamond (NCD) growth on different substrates, including silicon with and without different metallic interlayers, on aluminum nitride (AlN), and on a Si/AlN-based cantilever. It is shown that non-diamond substrate treatment prior to NCD growth is important for achieving high nucleation densities. AFM measurements reveal that an additional Si surface pretreatment with hydrogen plasma increases the nucleation density by a factor of four. A similar effect was indirectly demonstrated with acidic pretreatment of AlN. In both cases it is believed that the surface roughening is the key factor for explaining this phenomenon.

Thick (>150 μm) beryllium coatings are studied as an ablator material of interest for fusion fuel capsules for the National Ignition Facility (NIF). As an added complication, the coatings are deposited on mm-scale spherical substrates, as opposed to flats. DC magnetron sputtering is used because of the relative controllability of the processing temperature and energy of the deposits. We used ultra small angle x-ray spectroscopy (USAXS) to characterize the void fraction and distribution along the spherical surface. We investigated the void structure using a combination focused ion beam (FIB) and scanning electron microscope (SEM), along with transmission electron microscopy (TEM). Our results show a few volume percent of voids and a typical void diameter of less than two hundred nanometers. Understanding how the stresses in the deposited material develop with thickness is important so that we can minimize film cracking and delamination. To that end, an in-situ multiple optical beam stress sensor (MOSS) was used to measure the stress behavior of thick Beryllium coatings on flat substrates as the material was being deposited. We will show how the film stress saturates with thickness and changes with pressure.

The use of Voltage Waveform Tailoring (VWT) – that is the use of non-sinusoidal waveforms with a period equivalent to RF frequencies – is shown to be effective in modifying the electric field distribution in a parallel plate, capacitively coupled laboratory plasma deposition reactor, and thus in changing the growth mode of silicon thin films from amorphous to nanocrystalline. The use of the VWT technique allows one to decouple the power injected into the plasma from the ion-bombardment energy at the film surface without changing any other deposition parameters, such as pressure or gas mixture. Material results are presented for an H2/SiH4 gas composition. A “peaks” type waveform increases the ion-bombardment energy at the RF electrode and reduces it at the substrate, resulting in more nanocrystalline growth. The use of a “valleys”-type waveform has the opposite effect, and results in more amorphous growth. We show the dependence of the process on silane dilution and pressure, including results on changes to the deposition rate when changing the excitation voltage waveform.