Dark-Field Stigmatic Ion Microscopy for Structural Contrast Enhancement

摘要

Dark-field images are observed with a stigmatic (immersion objective lens) secondary ion mass spectroscopic ion microscope by means of eccentric objective aperture, and is a useful extension of shadow contrast imaging. The spatial resolution in these images is comparable with conventional bright-field imaging, provided that a narrow energy band pass is selected to minimize chromatic aberrartions. It is demonstrated that the dark-field method is useful for correlating surface relief with chemical contrast in the compositional secondary ion mass spectrospic mapping of conventional ion microscopy. Further, based on the information acquired in the dark-field imaging mode, digital techniques to compensate for asperity artifacts in conventional ion microscopy are proposed. Keywords: Ion microscopy; Microtopography; Mass spectrometry; Digital image processing; Surface characterization; Secondary ion mass spectroscopy; Reprints.