Site-Selective Analysis of Defect, Surface and Interface

Abstract

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 proposed. In this method, the x-ray photon energy dependence of a capacitance involved in various diode structures is measured. The capacitance is changed by an x-ray induced photoemission of a localized electron trapped in the low dimensional structures. Since the photoemission originates from the x-ray absorption of only the low dimensional structures, the site-selective analysis may be realized. Experiments using Schottky barrier diodes of A1GaAs: Se with a defect, ′DX center′, successfully indicate the site-selective XAFS spectra of the defect atom.