Mechanical properties of thin films grown by nanocluster deposition are highly dependent on the energy at which the clusters are deposited. Using molecular dynamics computer simulations we have quantitatively studied variations in the properties of copper thin films grown by deposition of Cu nanoclusters, at energies ranging from 5 meV to 10 eV per cluster atom, on a Cu (100) substrate.

We have been developing a low energy Ne atom scattering system combined with a time-of-flight spectrometer for insulator surface structural analysis. Insulator surface structure is difficult to study because of charging effects during electron or ion beam bombardment. Structural analyses of insulator surfaces are very important in fundamental research as well as technology fields. In our system, charged ion beams of 2 keV-Ne+ are converted into neutral beams by charge exchange with the same element gas after the primary beam passes through a chopper. Other features of this system are pulsed beams, time-of-flight measurements, and a micochannel plate (MCP) detector is coaxially mounted along the primary beam. This is a home made equipment. We will show the detection systems, as well.

He desorption in Fe was studied using rate theory and kinetic Monte Carlo models. A good fit to experimental observations was obtained with a migration energy of 1.1 eV and a formation energy of 1.6 eV for the single vacancy. These results could be explained by the presence of traps/impurities in experiments. Simulations show that the release of He during annealing is mainly due to the dissociative mechanism (Frank-Turnbull) and the release of Hei from He-V clusters.

Implantation with a variety of sub-MeV ions (He, Ar, Xe, O, and I) were performed on cubic single crystals of yttria-stabilized zirconia in order to assess the capability of such material to withstand high fluences as a confinement matrix for nuclear waste. In this work, we confronted the results of both Doppler Broadening using slow positron implantation spectroscopy (DB-SPIS) and the Rutherford Backscattering/Channeling spectroscopy (RBS-C) which are sensitive to lattice defects almost opposite in nature. In spite of their difference in defect specific sensitivity, and except for a precursory damage production stage almost exclusively exhibited by SPIS for very low doses (< 0.1 dpa), either techniques show a similar fluence dependence, which exhibits 3 stages starting respectively around 0.1, 2 and 3 dpa, regardless of the damaging ion. However, owing to the stage I plateau displayed in the variation of the DB-SPIS lineshape parameter, we were able to estimate an ion-mass dependence of the critical size of open-volume defects reached before the production of new predominant defects.

Reactive nanofoil coatings of magnetron-sputtered aluminum and nickel/vanadium bilayers were characterized for reliable debonding of segmented carbon composite or metallic structures to be used in future Army applications. We determined the initiation energies of multilayer stacks by discharging an electric spark from a fixed capacitor bank and varying DC voltage before and after low temperature annealing, which resulted in varying amounts of interfacial interdiffusion observable by Rutherford backscattering spectrometry (RBS). The propagation velocity of the reaction was also measured using high speed video photography. Significant increases in initiation energy and decreasing propagation velocities were observed with increasing anneal times and temperatures, in agreement with the RBS results and existing literature discussion of reaction mechanisms. Initiation sensitivity and propagation velocity were both impacted by varying the stoichiometric ratio of Al and Ni/V, and the propagation rate was also affected by the nature of the substrate. These results allow for the optimization of both reliable initiation and long term, low temperature storage stability of the final reactive coatings for debonding applications.

We present a method of determining elemental depth profiles with secondary ion mass spectrometry (SIMS) corrected by all non-linearities between the SIMS countrate and the elemental concentration caused by chemical matrix effects, resulting in an absolute concentration depth profile. The key to this method is a low dose ion implantation step of corresponding reference isotopes prior to SIMS depth profiling. Spectra evaluation is performed on the basis of a selfconsistent evaluation in which the depth dependent influence of the matrix is determined. The technique is demonstrated for sequentially high dose ion implanted Cd and Se in SiO2.

Self-assembled silicon carbide (SiC) nano-dots were fabricated on Si wafers by an organometallic ion beam deposition. The self-assembled SiC nano-dots have the shape of a tile, and were heteroepitaxial SiC on Si.

Pd deposits on Ni(111) have been studied by low energy ion scattering spectroscopy. We found that two different types of epitaxial growth exist: Pd[11 2]//Ni[11 2] and Pd[11 2]//Ni[11 2] at substrate temperature of 300 K. The Pd(111) planes grow as mixed domains of 50 % each. Surface alloying of the Pd-Ni system was confirmed for deposition at 300 K in which Pd atoms displace first-layer Ni atoms, with an outward displacement of 0.4 Å with respect to first layer Ni atoms.

The ion sputtering and implantation into GaAs(001) surface at 1-5 keV Se+ grazing ion bombardment have been investigated by computer simulation.The azimuth angular dependencies of sputtering and penetration yield at grazing incidence have been calculated. It was observed that these dependencies correlate the crystal orientation. The depth distributions of 1-5 keV Se ions implanted into GaAs(001) for several azimuth angles of incidence have been presented.

Biocompatible Glassy Polymeric Carbon (GPC) is used for artificial heart valves and in other biomedical applications. Although it is ideally suited for implants in the blood stream, tissue that normally forms around the moving parts of a GPC heart valve sometimes loses adhesion and creates embolisms downstream. Here we compare silver ion implantation and silver deposition, each of which strongly inhibits cell attachment on GPC. Inhibition of cell adhesion is a desirable improvement to current GPC cardiac implants. In vitro biocompatibility tests have been carried out with model cell lines to demonstrate that traces of silver can favorably influence the surface of GPC for biomedical applications.

We have demonstrated that iron ions implanted into silicon dioxide thin films form nanoscale clusters which can act as catalyst for carbon nanotube growth. We have implanted iron ions with an energy of 60 keV and three different doses (1014, 1015, and 1016 cm-2) into silicon dioxide thin films thermally grown on silicon substrates. We then used chemical vapor deposition (CVD) to grow carbon nanotubes on these ion implanted substrates with methane as the precursor gas. We studied the effect of ion implantation dose on the structural properties of the nanoscale clusters, as well as the carbon nanotubes nucleated from these clusters. The nanoscale clusters and grown nanotubes were characterized by Atomic Force Microscopy and Raman spectroscopy. The electrical characteristics of the as-grown nanotubes were also characterized. We found that growth of low density, horizontal, and small diameter carbon nanotubes on silicon dioxide is possible using this nucleation technique.

Fabrication of domains containing graphitic structures in amorphous carbon (a-C) films was demonstrated. Amorphous carbon thin films with 200 nm thickness were deposited on Si substrates by ion-beam sputtering. Iron atoms in a range from 4×1013 to 3.7×1016 cm-2 were doped to the a-C films by an ion implantation technique through a nickel mask with a grid of square windows of 500×500 μm and a net of 50 μm in width as a template. After removing the metal mask, the partly Fe-containing a-C films were exposed to a low-energy electron shower. In the regions where Fe atoms were implanted, Fe were crystallized and preferably diffused toward the film surface leaving graphitic structures more than 10 nm in size in the interior of the amorphous carbon films. On the other hand, the masked regions, where Fe atoms were not implanted, remained amorphous. The results suggest that regions, which consist of amorphous domains and graphitic domains, can be intentionally arranged in a-C thin films.

Internal stresses can cause de-lamination and fracture of coatings and structures and it is well known that ion-implantation can be used to control such behavior through modification of the stress. Here, however, we show that the unique ability of implantation to create controlled stresses in materials by altering both the chemical composition and mechanical properties, combined with an increase in the bending strength of materials, can used to create novel vertical nanostructures. Silicon cantilevers (beams), 193nm thick, 200nm wide and 3μm long, were implanted with carbon ions to create a buried SiCx layers. The internal stresses generated by implantation caused the beams to bend at angles ranging from 10 degrees to greater than 90 degrees, leading to unique vertical nanostructures. This method can be used to create 3-D nano electromechanical systems (NEMS).

Multilayered and nanostructured coatings of amorphous carbon (DLC), silicon composite multilayers and nanocluster containing films today have great potential for applications as hard coatings, wear reduction layers and as diffusion barriers in biomaterials. Plasma immersion ion implantation and deposition (PIII&D) is a powerful technique to synthesize such films. The quantitative nanoscale analysis of the elemental distribution in such multielemental films and thin film stacks however is demanding.

In this paper it is shown how the high spatial resolution capabilities of energy filtered trans-mission electron microscopy (EFTEM) chemical analysis can be combined with accurate and standard-less concentration determination of ion beam analysis (IBA) techniques like Rutherford Backscattering Spectroscopy (RBS) and Elastic Recoil Detection Analysis (ERDA) to achieve absolute and accurate multielement concentration profiles in complicated nanomaterials.

Generation of extreme ultraviolet (EUV) light for nanolithography requires the use of hot, dense plasmas. Gas discharge produced plasma (GDPP) and laser produced plasma (LPP) are the primary configurations used to generate these plasmas. Both GDPP and LPP collector mirror systems face serious issues regarding lifetime and EUV light reflectivity performance. For both configurations debris, fast ions, fast neutrals, and condensable EUV radiator fuels (Li, Sn) interact with nearby collector mirrors. Sn, in particular is used due to its high conversion efficiency in the 13.5-nm in-band spectrum. In addition to debris, collector mirrors are exposed to impurities (H,C,O,N), off-band radiation (depositing heat) and highly-charged ions leading to their degradation and consequently limiting 13.5 nm light reflection intensity.

This work presents results of Ru and Rh-based collector optics irradiated by Sn ions between at 1.3 keV and exposed to Sn thermal atoms at room temperature. In-situ metrology monitors the effects of ion implantation on ion-induced erosion and EUV reflectivity changes using low-energy ion scattering spectroscopy and X-ray photoelectron spectroscopy. Results find that Sn implants at the first few monolayers leading to a mixed layer at the surface. Sn thermal atoms deposit on top of the mirror surface leading to 10-20% loss of collector mirror EUV light reflectivity.