Development of the measuring system for correlated thermal diffuse scattering using a low energy electron diffraction optics

本课题的研究目的是利用标准的低能电子衍射（LEED）光学器件实现相关热扩散散射（CTDS）的表面结构方法的实验系统的开发。广泛应用的LEED光学器件使CTDS方法在表面科学中得到广泛应用。首先，我们搭建了一个CTDS-LEED仪器，该仪器配备了LEED光学器件、五轴采样机械手和CCD摄像机。LEED光学和图像采集功能由一台个人计算机控制。我们已经确认该系统具有足够的性能来测量CTDS。此外，我们还编写了一个计算机程序来实现CTDS测量的自动化，并编写了一个程序来分析CTDS数据的表面结构。我们可以使用这些程序访问大部分衍射特征，即布拉格点，CTDS和其他漫射结构。利用现有的系统和程序，数据采集效率提高到原来系统的10到100倍。利用该体系对Si(111)4 × 1- in表面进行了表面结构分析。该系统的高性能已被证实是一种表面结构工具。为了推广现有的表面分析方法（CTDS-LEED），我们将广泛公开现有的结果，并将分发用于测量和分析的程序。

The purpose of this research project is the development of the experimental system that realizes the surface structure method of the correlated thermal diffuse scattering (CTDS) using a standard low energy electron diffraction (LEED) optics. The utilization of the widespread LEED optics help the CTDS method come into wide use in surface science. First, we constructed an apparatus of CTDS-LEED, which were equipped with a LEED optics, a 5-axes sample manipulator and a CCD video camera. The functions of the LEED optics and image acquisition are controlled by a personal computer. We have confirmed that the system holds the enough performance to measure CTDS. Furthermore, we have made a computer program to automate the CTDS measurements, and a program to analyze the surface structure from CTDS data. We can access most of the diffraction feature, i.e. Bragg spots, CTDS and other diffuse structures, using these programs. With the present system and programs, the data acquisition efficiency have increased to 10 or 100 times of that using the previous system. The surface structure analysis was performed for Si(111)4x1-In surface using the present system. The high performance of the present system have been confirmed as a surface structural tool. In order to spread the present method (CTDS-LEED) for surface analysis, we will widely open the present results and will distribute the programs for measurements and analysis.