A size-selected Ar gas cluster ion beam (GCIB) was applied to secondary ion mass spectrometry (SIMS) of a polystyrene (PS) thin film, a 1,4-didodecylbenzene (DDB) thin film, and an ITO glass sample. Additionally, the samples were analyzed by SIMS using an atomic Ar⁺ ion projectile and X-ray photoelectron spectroscopy (XPS). All three samples were contaminated by poly(dimethylsiloxane) (PDMS) on the surface. Compared to the Ar⁺ SIMS spectra, the fragments in the PS and DDB SIMS spectra for Ar₁₅₅₀⁺, including siloxane, were enhanced more than ∼100-fold, while the hydrocarbon fragments were enhanced 10-20-fold. XPS spectra during beam irradiation indicate that Ar-GCIB sputters contaminants on the surface more effectively than the atomic Ar⁺ ion beam. These results indicate that a large gas cluster projectile can sputter a much shallower volume of organic material than small projectiles, resulting in an extremely surface-sensitive analysis of organic thin films. The shallow volume sputtering by GCIB is responsible for the preferential enhancement of the surface contaminants.

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  ZnO nanorods were synthesized on ZnO seed layer covered sapphire substrates with different orientations by hydrothermal method. The surface morphologies of ZnO seed layer were analyzed by atomic force microscope. The shapes of ZnO nanorods were characterized by scanning electron microscopy. The c-axis oriented ZnO nanorods along surface normal were synthesized on A-plane and C-plane sapphire substrates. While, ZnO nanorods grown on R-plane sapphire were slant to the substrate and crossed each other.

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  We have investigated ion-beam irradiation effects on the growth of carbon nanotubes (CNTs) in the SiC surface decomposition method. A SiC(0001) surface was irradiated by Ar⁺ ion with 1 or 5 keV for 1 h and then annealed at 1700℃ for 2 h at a pressure of 2×10⁻² Pa. We found that the CNTs grown on the surface with 1 keV Ar⁺ ion irradiation are longer than CNTs grown without Ar⁺ ion irradiation. In the case of Ar⁺ ion irradiation at 5 keV, short CNTs are formed on the surface. These results indicate that damage to the SiC(0001) surface affects the CNT formation in the SiC surface decomposition method.

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  In this study, carbon films were deposited on the surface of a needle specimen of tungsten by an electrolysis method in a methanol solution. The carbon film growth and interface state have been investigated in atomic events by field ion microscopy. At high electrolytic current, carbon films preferentially condense on a W{111} plane, and the interfacial reaction in the carbon atom-tungsten substrate interface is also intensive. On the other hand, the tungsten substrate surfaces are entirely covered with carbon atoms of pseudomorphic structure in the case of a low electrolytic current. Field emission characteristics for various coverages of the carbon film were also evaluated.

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  Plasma density is estimated from the target voltage and current characteristics of the pulse modulator circuit in plasma-based ion implantation. The voltage recovery time constant directly reflects the ion sheath characteristics, and the sheath resistance is related to the ion density inside the transient sheath. The stationary current also provides information on the sheath parameters. The ion density obtained by equating the measured characteristics with an equivalent circuit can be converted to plasma density using a continuity equation. Thus, the plasma density is estimated can be controlled by the degree of vacuum and the applied voltage.

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  Plasma-based ion implantation (PBII) is a technique used to modify the surface of samples by immersion in plasma and application of a negative bias voltage to the target. In this study, we showed the PBII was realized using the self-ignition plasma induced by a pulsed bias voltage. Electric discharge properties of the self-ignition plasma were investigated in Ar and N2. The minimum voltage necessary for the plasma generation was expected to be controllable by the pressure and the pulse width.

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  We investigated the influence of the work function of metal gate electrodes on the current component induced by exposing silicon nitride-silicon oxide double-layer films to high-energy ultraviolet (UV) illumination. Prior to UV exposure, the conduction current under negative gate bias through an aluminum-nitride-oxide-silicon structure was larger than that through a mercury-nitride-oxide-silicon structure. In these structures under negative gate bias, it has been considered that electrons injected from the metal electrodes into the nitride films dominate the conduction current. Hence, the experimental result can be explained by the notion that the probability of electron injection into the nitride film from the aluminum electrode is higher than that from the mercury electrode because of the difference of the work function between the two kinds of metals. After UV exposure, the conduction current under negative gate bias through both the structures were almost identical to each other. This result reveals that the current component after exposure to UV illumination is dominated by charge carriers generated in the bulk of the nitride film.

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