Capacitance XAFS method: X-ray absorption spectroscopy of low-dimensional structures

For local structure analyses of low-dimensional structures in semiconductors, such as defects, interfaces and surfaces, a new site-selective X-ray absorption fine structure (XAFS) measurement, `capacitance XAFS method', is presented. This method measures the X-ray photon energy dependence of the capacitance involved in diode structures. Since the capacitance is changed by an X-ray induced photoemission of localized electrons in the low dimensional structures, a site-selective analysis can be made. Although macroscopic X-ray absorption can be measured by conventional XAFS analyses, low-dimensional X-ray absorption coefficients are observed by the capacitance XAFS measurements.