Minoda H, Hatano K, Yazawa H
Department of Applied Physics, Tokyo University of Agriculture and Technology, Koganei, Tokyo 184-8588, Japan.
Rev Sci Instrum. 2009 Nov;80(11):113702. doi: 10.1063/1.3251272.
The surface conductivity measurement system using a micro-four-point probe (M4PP) had been developed for the ultrahigh vacuum transmission electron microscope (UHV-TEM). Since the current distribution in the sample crystals during the current voltage measurement by the M4PP is localized within the depth of several micrometers from the surface, the system is sensitive to the surface conductivity, which is related with the surface superstructure. It was installed in the main chamber of the TEM and the surface conductivity can be measured in situ. The surface structures were observed by reflection electron microscopy and diffraction (REM-RHEED). REM-RHEED enables us to observe the surface superstructures and their structure defects such as surface atomic steps and domain boundaries of the surface superstructure. Thus the effects of the defects on the surface conductivity can be investigated. In the present paper we present the surface conductivity measurement system and its application to the Si(111)-square root(3) x square root(3)-Ag surface prepared on the Si(111) vicinal surfaces. The result clearly showed that the surface conductivity was affected by step configuration.
一种使用微四点探针（M4PP）的表面电导率测量系统已被开发用于超高真空透射电子显微镜（UHV-TEM）。由于在通过M4PP进行电流电压测量期间，样品晶体中的电流分布局限于距表面几微米的深度范围内，该系统对与表面超结构相关的表面电导率敏感。它被安装在TEM的主腔室中，并且可以原位测量表面电导率。通过反射电子显微镜和衍射（REM-RHEED）观察表面结构。REM-RHEED使我们能够观察表面超结构及其结构缺陷，如表面原子台阶和表面超结构的畴界。因此，可以研究这些缺陷对表面电导率的影响。在本文中，我们介绍了表面电导率测量系统及其在Si(111) 近邻表面上制备的Si(111)-√3×√3-Ag表面的应用。结果清楚地表明，表面电导率受台阶构型的影响。
