Surface roughening processes in the molecular beam epitaxy growth of GaAs are studied by in-situ scanning electron microscopy. Three types of onset of three dimensional growth, pure 3D growth, coexistence of 3D and 2D growth, and 2D to 3D transition are observed.

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Equilibrium concentration of point defects under various stages in growing silicon crystal is theoretically examined. Formulas of concentration of point defects corresponding to solid-liquid interface, early cooling stage and including secondary defects are proposed. It is suggested that equilibrium concentration is not unique and that previous consideration is not applied for actual crystal growth.

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The behavior of monolayer holes on GaAs(001) surface during post-growth annealing in molecular beam epitaxy (MBE) is examined in detail by in-situ scanning electron microscopy (SEM). Submicron scale, nearly rectangular, monolayer deep holes are formed after small islands and holes are eliminated. Their growth and shrinkage are found to proceed asymmetrically: For example, they grow only into the right side, and shrink only from the top. The mechanism is discussed in terms of step activity. It was found that in the regrowth after annealing, three dimensional islands are formed preferentially on the step edges.

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Oxygen concentration in silicon Wafers has been determined by infrared emissivity measurement. As for the five measured samples, CZ silicon wafers with oxygen contents ranging from 3 to 10× 10¹⁷cm^-3 and thickness of 2.0 and 0.6mm were prepared. The good relationship for the oxygen concentration and the infrared absorption coefficient in each silicon wafer has been obtained between the differential transmission spectra and the defferential emissivity spectra. Moreover, it was clarified the emissivity measurement needed the calibration for lattice vibration absorption αe at a measured temperature for its accuracy.
In the results, the emissivity measurement showed its capability of the quantatitive method for the oxygen concentration and absorption in a silicon wafer. Therefore, this method seems to be effective for the half polished thin wafer-sized samples.

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Microdefects in Czochralski grown silicon single crystals have been investigated by transmission electron microscopy, infrared absorption spectroscopy, X-ray topography and etching technique. Swirl defects were identified as interstitial perfect dislocation loops and silicon oxide precipitates. Swirl oxide precipitates emit dislocation loops and stacking faults on thermal oxidation. Stacking fault growth was found to obey the Bardeen-Herring source mechanism, and to proceed through the absorption of silicon interstitials emitted by oxygen precipitation. Crystal growth under the supercooled condition is effective to suppress the defect introduction because growth rate fluctuation as well as oxygen dissolution from the quartz crucible are reduced.

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Surface roughening processes in the molecular beam epitaxy of GaAs are studied by in-situ scanning electron micros-copy. Three types of onset of roughening are observed, that is, smooth-to-rough change, coexistence of rough and smooth growths and purely rough growth. The results are compared to the quasi-smooth growth and to the growth of silicon on (111) surface, and the roughening mechanism is discussed.

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It is found that the secondary electron intensity from GaAs(001) surfaces, during molecular beam epitaxy (MBE) growth, relates to the work function (WF). Quantitative theoretical evaluation of the WF for the surface reconstructions was performed using the electron counting model. The relative and absolute values of WF agree well with the reported values. The WF for the other components, mixed compositions and surface reconstruction can be predicted.

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In proportion to the extent of down-scaling of silicon devices, surface microroughness causes more serious problems in device performance. Scanning probe microscopes were used as a powerful tool to evaluate the surface microroughness. In order to investigate the influence of heavily doping on surface morphology, heavily phosphorus doped samples of both Si(100) and polycrystalline silicon together with non-doped ones were examined using atomic force microscopy (AFM). Comparing to a smooth surface moderately doped Si(100) and heavily P-doped Si(100) surfaces exhibited unique geometrical AFM image patterns. The characteristic features of the patterns remained almost unchanged by annealing. The unique pattern still exists on the surface of 50 nm thick thermal oxide films of P-doped Si(100). Moreover, after removal the oxide film, the SiO₂/Si interface also showed a similar pattern, though it was somewhat diffused. In the case of polycrystalline silicon, the grain size increased with heavily doping, but the unique pattern was not observed.

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分子線結晶成長法（ＭＢＥ）によりInP基板上のInAsSbN赤外量子井戸レーザダイオードを作製し、その発光特性のアニール効果について調べた。その結果、６００℃、３０秒のアニールにより、低温においては、発光強度は約一桁増大し、ピーク波長も１５meV高エネルギー側にシフトした。ただし室温付近においては、発光強度の増大はほとんど観測されずピーク波長のシフトも観測されなかった。またアニールによりレーザ発振閾値がわずかに低下し、２１０Ｋにおいて波長2.28μｍのレーザ発振を実現することが出来た。

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