Fabrication of novel functional surfaces through ionic crystal / semiconductor heterostructurse and their properties

总结了目前的研究结果。(1)Mg和Ba薄膜的初始氧化过程的电子光谱研究MgO和BaO，这是晶格匹配的GaAs和Si，可以预期的关键材料集成功能钙钛矿氧化物与高度发达的半导体技术。本文利用俄歇电子能谱、电子能量损失谱和紫外光电子能谱研究了Mg和Ba薄膜的初始氧化过程。氧化的条件，如临界氧暴露，适当的衬底温度等已被澄清。(2)用高灵敏度RHEED分析评价碱金属卤化物异质结界面用反射高能电子衍射（RHEED）分析了碱金属卤化物异质结界面。这种方法的缺点是探测电子会对生长中的薄膜造成损伤。在目前的工作中，我们设计了高灵敏度的RHEED应用程序 ...更多信息 采用微通道板（MCP），可将探测电流降低1/8000。利用该装置可以观察到碱金属卤化物薄膜的初始生长过程，并详细阐明了其生长机理。(3)在GaAs衬底上制备岩盐氧化物薄膜的复合异质结构通过在GaAs（001）衬底上制备具有两个碱金属卤化物缓冲层的复合异质结构，在GaAs（001）衬底上生长了单晶MgO薄膜。与直接在GaAs（001）上生长MgO相比，生长温度降低到150 ℃。生长的薄膜的电子能量损失谱与体相MgO的电子能量损失谱一致，表明保持了表面化学计量比。在超高真空条件下，该结构在高达600摄氏度的温度下仍保持稳定。复杂异质结构的概念将有助于在GaAs衬底上制备功能氧化层，并导致氧化物/半导体集成器件。(4)碱金属卤化物/半导体异质结光产额的测量我们设计了一种新的测量薄膜表面光产额的装置。到目前为止，已经测量了不同NaCl厚度的NaCl/GaAs异质结的光产额。这提供了光阈值的电子发射和添加剂上的异国情调的异质结构，如NaCl/GaAs的带对齐的信息。少

The results of the present research are summarized.(1) Initial oxidation process of Mg and Ba films studied by electron spectroscopiesMgO and BaO, which are lattice matched to GaAs and Si, could be expected to be key materials to integrate functional perovskite oxides with highly developed semiconductor technologies. In the present work we have revealed the initial oxidation process of Mg and Ba films using Auger electron spectroscopy, electron energy loss spectroscopy and ultraviolet photoelectron spectroscopy. The conditions of oxidation such as critical oxygen exposure, appropriate substrate temperature, etc. have been clarified.(2) Evaluation of alkali halide hetero-interface by high sensitive RHEED analysisThe interface of alkali halide heterostructures have been analyzed by reflection high energy electron diffraction (RHEED). The disadvantage of this method is that the probing electron causes damage to the growing film. In the present work we have devised high sensitive RHEED app … More aratus using micro channel plate (MCP), which could reduce the probing current by as much as 1/8000. With this apparatus we could observe the initial growth process of alkali halide films and clarified the mechanism in detail.(3) A complex heterostructure to achieve a rocksalt oxide film on GaAsA single-crystalline MgO film was grown on GaAs(001) by constructing a complex heterostructure with two alkali halide buffer layers. The growth temperature was decreased to 150 ﾟC as compared with direct growth of MgO on GaAs(001). Electron energy loss spectrum of the grown film agreed well with that of bulk MgO, indicating that surface stoichiometry was maintained. The structure was stable up to 600ﾟC against heating in UHV condition. The concept of a complex heterostructure will help fabrication of functional oxide layers on GaAs substrates and lead to oxide/semiconductor integrated devices.(4) Photoyield measurement of alkali halide/semiconductor heterostructureWe have devised a new apparatus to measure a photoyield from the film surface. The photoyield from the NaCl/GaAs heterostructure with various NaCl thickness have been measured up to now. This provides the photo threshold for the electron emission and additive information on the band alignment of the exotic heterostructure such as NaCl/GaAs. Less