[en] A chemical bond generated by the interaction between low energy ion and base was investigated by ab initio molecular orbital method. The effects of ion charge were studied by calculation of this method. When carbon ion approached to graphite base (C₂₄H₁₂), the positive ion and the neutral atom covalently bonded, but the negative ion did not combine with it. When carbon ion was injected into h-BN base (B₁₂N₁₂H₁₂, hexagonal system boron nitride), the positive ion and the neutron atom formed covalent bond and the van der Waals binding, and the negative ion interacted statically with it. (S.Y.)

[en] The electronic structure of an incident carbon ion on a graphite surface is discussed on the basis of ab initio molecular orbital calculations. A carbon cation forms a covalent bond with the graphite, and a carbon nonion is attracted to the graphite surface through van der Waals interaction. A carbon anion has no stable state on a graphite surface. The charge effects of incident ions become clear upon detailed examination of the electronic structure. (author)

[en] Ion beam process is the technology for creating new functional materials by ionizing atoms and molecules in vacuum, and irradiating material surfaces with them. It is the technology indispensable for semiconductor industry, and it is applied to form wear resistant or corrosion resistant surface layer. There is the possibility of impurity mixing in the functional surface layers made by ion beam process. In this case, a large amount of ion irradiation is required, consequently, the ion current density is large, and the irradiation time is long, therefore, the amount of impurities becomes a problem. In this research, the analysis was carried out for metallic impurities when functional thin films were formed by dynamic mixing process. For the analysis, activation analysis method was used. The activation analysis method which can measure trace elements is explained. When functional thin films are formed, it is important that the functions can be controlled arbitrarily by the forming conditions, and that the films stick to substrates with sufficient strength. Dynamic mixing process can satisfy these requirements. In the experiment, the silicon thin films made with two dynamic mixing apparatuses were examined. The causes of impurity mixing were acceleration electrode and argon atmosphere. (K.I.)

[en] Nitrogen-containing films of chromium and titanium were prepared by evaporation of the metal under simultaneous bombardment with highly energetic nitrogen ions. Under identical preparation conditions, i.e. ion energy, ion current density, temperature, evaporation rate, and gas pressure, titanium forms a single phase film of δ-TiN whereas chromium shows phase mixtures of Cr, Cr₂N and CrN with a lower nitrogen content than the corresponding titanium film. This different behaviour of Cr compared to Ti is attributed to the differences in chemical reactivity and in thermodynamic stability of the nitrides. The results show that chemical driving forces play a decisive role in ion-beam-assisted film synthesis. (orig.)

[en] A microbeam line for MeV heavy ions of almost any element has been developed for microion-beam processing such as maskless MeV ion implantation and its in-situ analysis. Beam spot sizes of 4.0 μm x 4.0 μm for 3 MeV C²⁺ and 9.6 μm x 4.8 μm for 1.8 MeV Au²⁺ beams were obtained. Maskless MeV gold ion implantation to a silicon substrate and in-situ microanalysis before and after ion implantation were demonstrated. (author)

[en] A buried layer of crystalline SiC in silicon wafer is synthesized by 1.5 MeV C⁺ implantation with a dose of 1.5 x 10¹⁸ ions/cm² at a high temperature of 880degC. The infrared absorption spectra of this sample shows formation of the SiC crystal, and its crystal structure is found to be of the 3C type (β-SiC) from the X-ray diffraction pattern. The rocking curve shows that crystallographic orientation of the SiC buried layer is aligned with the lattice of the Si substrate. (author)

[en] The initial stages of TiN crystal growth on Si substrates in the dynamic mixing method were investigated by reflection high-energy electron diffraction (RHEED) in a newly constructed ultrahigh-vacuum apparatus. The Si (001) RHEED pattern disappeared immediately after dynamic ion beam mixing started, and then was replaced by the halo pattern representing amorphous structures. The halo gradually changed to Debye-Scherrer rings representing Ti polycrystal. The results for Si (001) and (111) substrates have confirmed that the TiN crystal is controlled by the arrival ratio, Ti/N. The present RHEED pattern study has, for the first time, revealed an observable influence of the crystallography of Si substrates on TiN crystal growth. (author)

[en] A focused ion beam line of MeV heavy ions has been developed by combining a focusing system consisting of objective slits and a magnetic quadrupole doublet to the beam line of a tandem-type accelerator. The demagnification factors of this system were determined to be 1/3.4 for the horizontal direction and 1/14 for the vertical direction, and a minimum beam spot size of 5.6 μm x 8.0 μm was achieved. This system allows us ion beam processes such as maskless MeV ion implantation and ion beam microanalysis using heavy ions. (author)

[en] A microbeam line for MeV heavy ions was developed by combining a focusing system to a beam line of tandem-type accelerator at GIRIO (Government Industrial Research Institute Osaka). Beam size of about 3μmx3μm for various ions such as carbon or gold ions have been achieved. This system enables us not only microion-beam processing such as maskless MeV ion implantation but also ion beam microanalyses with RBS, PIXE using MeV heavy ions as a microprobe. (author)

[en] Multi-dimensional structure fabricated by maskless MeV gold implantation in silicon wafer was analyzed by 3 MeV carbon ion microprobe using a microbeam line developed at GIRIO. The minimum line width of the implanted region was estimated to be about 5 μm. The advantages of heavy ions for microanalysis were demonstrated. (author)