Surface "element" imaging by a new scanning probe microscopy

点击翻译按钮获取中文摘要

The main research results related to this project are as follows.2001(1)We installed a new probe microscopy developed in this project into a beamline of the synchrotron radiation facility, Spring-8. We found that a valence state modulation owing to an inner-shell excitation can be detected by capacitance under the x-ray irradiation.(2)The photon energy dependence of a local capacitance detected by the microprobe indicated an x-ray absorption fine structure (XAFS) spectrum of the sample surface. This finding indicates that the scanning image with surface chemical information, such as element and its bonding states, can be obtained by this method.(3)We demonstrated an advanced site-selectivity ; the control of bias voltage applied to the microprobe selects the observable bonding state.(4)As an industrial application of this method, we successfully observed the site-selective XAFS spectrum of a conduction channel with 〜nm thickness in a transistor.2002(1)We observed various sample surfaces, and reached our project goal: establishment of the surface "element" imaging technique.(2)The advantage of this technique is typically shown in our research: element and structure analyses of electron trap in ultra-thin oxide on semiconductor surface.(3)Simultaneous measurement of the local structure and its electric property by the microprobe is successfully achieved.(4)This capacitance detection technique revealed the interface state of buried quantum dot structure. The site-selectivity involved in this technique makes us possible to analyze the inside of the nano-electric devices.(5)The XAFS spectrum is predictable by molecular orbital calculation. This result shows the reliability and a general guideline for spectrum analysis of this method.