One of the factors inhibiting the soldering on an Au electrode is that the underlying metal diffuses onto the surface of Au electrodes and an oxide layer is formed. In order to prevent any faults, the evaluation method of the underlying metal diffusion was examined. Usually, surface analytical techniques such as Auger electron spectroscopy and X-ray photoelectron spectroscopy are used for the evaluation of the underlying metal diffusion; however, a more rapid method is required for process management. We examined the measurement of the diffused underlying metal by energy dispersive X-ray spectroscope equipped to a low voltage scanning electron microscopy (SEM-EDX). It is possible to evaluate the underlying metal diffusion without detecting the underlayer signal by using SEM-EDX. It is suggested that measurements of the diffused underlying metal with SEM-EDX can be applied to the process management.

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The growth modes of Ba deposited on a Mo (110) substrate have been investigated by using reflection high-energy electron diffraction (RHEED) and scanning electron microscopy (SEM). In this study, the RHEED specular beam intensity oscillations apparatus is employed to confirm the surface flatness of thin Ba layers on Mo(110) substrate. Ba grows on the Mo(110) substrate via the Stranski-Krastanov growth mode in the temperature range between 300 and 550 °C, in which a monolayer with a (1.5×1.8) structure grows initially, followed by the growth of Ba islands with the (111)_Ba plane. Between room temperature (R.T.) and 300 °C, Ba grows on the Mo(110) substrate via the Frank-van der Merwe growth mode, however only several periods of RHEED specular beam intensity oscillations could be observed. Such results suggest that several flat Ba layers grew on Mo(110) substrate via Frank-van der Merwe growth mode and Ba layers have much difficulty in keeping the surface flatness on a Mo(110) substrate. In the temperature range from 300 to 550 °C, only single oscillation was observed, suggesting that the Ba/Mo(110) system adopts the Stranski-Krastanov growth mode at such temperatures with the (1.5×1.8) monolayer.

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The measurement conditions of metastable de-excitation spectroscopy (MDS) were investigated in order to apply MDS to the study of the electronic structure of MgO films used for plasma display panels (PDPs). It was demonstrated that positive charging induced on the surface of the MgO film of 50 nm thickness during the MDS measurement can be avoided by employing a low flux of primary metastable He atoms. The positive charges accumulated by successive MDS measurements were found to be completely removed by irradiation of keV electrons, in which the neutralization by the re-distribution of secondary electrons emitted by the keV electron irradiation plays an important role [J. Surf. Anal. 12, 284 (2005)]. The changes in the MDS spectra due to the heating treatment of the MgO film, which is one of the processes employed in the fabrication of PDPs, was investigated, and the ionization potential given as a sum of the band gap and the electron affinity was found to decrease with the increase in the heating temperature. Heating the MgO film at 500 °C in vacuum is effective to clean the surface but not sufficient to completely remove contaminations on the surface, and repeating sputtering and heating at 500 °C is required to clean the MgO film surface. The electronic structure of the clean surface of the MgO film of 50 nm thickness was found to be the same as that of 500 nm thickness, the thickness of which is a typical value for the MgO film used in PDPs. This result revealed that 50 nm thick MgO films, in which effects of charging is much less than those for 500 nm thick films, can be used to evaluate the electronic structure of the MgO film surface. The present results confirmed that MDS is one of the effective techniques to evaluate properties of MgO films used for PDPs.

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Dependence of the electron-induced damage of the clean and carbon-contaminated SiO₂ film surfaces during the Auger electron spectroscopy measurement was investigated under irradiation of electrons at different primary energies. The variation in the intensity of the Si-LVV elemental peak with the increase in the electron dose was measured and analyzed within the scheme of the two-step decomposition model [J. Surf. Sci. Soc. Jpn. 25, 212 (2004) (in Japanese)]. The results clearly revealed that the rate of the decomposition of SiO₂ induced by the electron irradiation is decreased by a small amount of carbon contaminations of ∼0.03 nm thickness on the SiO₂ surface. The effects of carbon contaminations on the reduction in the electron-induced degradation of SiO₂ is significant for the low-primary energy of electrons of 3 keV, and no effects were confirmed at the primary energy of 15 keV. These findings suggest that the primary energy dependence is attributed to the fact that interactions between primary electrons and atoms in the near surface region is much significant when primary electrons with the lower primary energy are irradiated.

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光電子分光法のもつポテンシャルは，関連技術の発展によってさらに高まっている．測定技術の進歩によって信号雑音（SN）比が向上したことで，従来の突然近似では取り扱えない，光電子分光のエキストリンシックなエネルギー損失に再び注目が集まるようになっている．また，超短レーザーパルスと最新のレーザー技術によって時間分解光電子分光法が実現された．本稿では，エキストリンシックなエネルギー損失と時間分解光電子分光に関するいくつかの研究について紹介する．

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