Doping by single Ion Implantation and its application to solid state materials and devices.

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Development of the single ion implantation (SII) was conducted for the purpose of implanting accurate number of dopant ions one by one into ultra fine semiconductor structures. By evaluating the number of implanted ions and detection efficiency of the single ion incidence, the SII has been proven to be effective in suppressing the fluctuation in dopant number 50% less than the conventional ion implantation.Immunity of VLSIs against transient malfunction induced by single ion irradiation was investigated using single ion microprobe technique, and sensitive site in the VLSIs and mechanism of the malfunction have been identified.Damages introduction with ion irradiation and subsequent anisotropic etching have yielded Si nano-wires successfully.The enhanced gold plating was observed at the nano-modified silicon surface using SII.The temperature dependence of Schottky barrier I-V characteristics revealed that near surface damages in Si introduced by ion irradiation reduced the Schottky barrier height due to fermi level position at the metal-semiconductor interface.Ion implantation induced defects were investigated by positron annihilation technique and the relationship between their depth profile and ion species was clearly established.For the next stage intense positron beam, high efficiency positron moderators were developed together with the use of ^<60>C source. At present, the result that guarantees the thousand times high efficiency moderation was obtained.Processes of oxidation, H_2 desorption and adsorption of alkaline metals on Si surfaces have been clarified using molecular orbital calculations. Energy changes along the 7x7 formation steps and the effect of oxygen atoms was calculated.Dynamic growth steps of the DAS domains were precisely observed in-situ using high temperature STM.Isolated DAS domains nucleated or annihilated with a single stacking fault triangle as a building unit and the critical nucleus size for growth was revealed.