Submicron-resolved X-ray topography using asymmetric-reflection magnifiers

This paper describes a study of synchrotron-radiated X-ray topography in which a topographic image was magnified by asymmetric reflection (ASR) to obtain submicron resolution. The samples used were trenched Si(100) wafers. Three diffraction schemes were used: Si-022 anomalous transmission with Si-311 ASR magnification (E=8.8 keV), Si-044 Laue-case reflection with Si-511 ASR magnification (E=21.4 keV), and Si-440 Bragg-case reflection with Si-311 ASR magnification (E=8.8 keV). Grazing angles in the ASRs were 0.28–0.36°, which were 1.6–3.4 times corresponding critical angles. In these experiments, we obtained one-dimensionally expanded topographs, and the minimum spatial resolution reached was below 1 μm. A theoretical study provided the limits of the spatial resolutions, some of which are less than 0.1 μm if Si-crystal ASR magnifiers are used.