| Budget Amount *help |
¥5,400,000 (Direct Cost: ¥5,400,000)
Fiscal Year 1997: ¥1,200,000 (Direct Cost: ¥1,200,000)
Fiscal Year 1996: ¥4,200,000 (Direct Cost: ¥4,200,000)
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| Research Abstract |
The following aspects concerning elastic and inelastic scattering electrons constructing a RHEED pattern were made clear by energy filtered RHEED method. 1. Removing the inelastic scattering components from a conventional RHEED pattern, the contrast of the diffraction pattern becomes higher as a result of decreased background intensity and disappearance of Kikuchi lines. (1) For Si (001) 2xl surface, a lone pattern, which is produced by a disordering of the c(4x2) structure, was extracted clearly from the background. (2) For a vicinal Si (111) 7x7 surface, some extra spots in the vertical line across the specular spot were found in the zero-loss RHEED pattern. It was demonstrated that these extra spots can be explained by a regular step surface. (3) For the gamma phase structure of Al on Si (111), the surface structure was kinematically analyzed as 9x9 incommensurate one from the zero-loss pattern. 2. In order to investigate the loss energy of inelastic scattering electrons, energy los
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s spectroscopies were measured for several diffraction beams, Kikuchi line and background. It was found that RHEED beams suffer surface plasmon loss strongly and the magnitude of surface plasmon loss depends on both the glancing angle of incident beam and the take-off angle of the diffraction beam. 3. It was found that a conventional rocking curve differs from the zero-loss one in the relative intensity. The relative intensity of a peak at lower angle side decreases as removing the inelastic components. This means that more grazing electron beam suffers surface plasmon loss with higher probability. It was proposed that such decreased peak intensity can be phenomenologically treated in the dynamical calculation of the rocking curve by introducing an spread imaginary potential toward vacuum. 4. In the beginning of the study on RHEED oscillation mechanism focused on inelastic scattering intensity, the difference of Al growth mode at room temperature on the two different substrates, Si (111) 7x7 and Si (111) 3x 3-Al surfaces, was examined. It was found that Al deposition on 7x7 surface reveals island growth mode, however, that on 3x 3-Al surface layr by layr growth mode but imperfect. Less
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