Reconstruction of three-dimensional chemistry and geometry using focused ion beam microscopy

A technique to reconstruct high resolution three-dimensional structural images and chemical maps using focused ion beam microscopy is presented. A focused ion beam microscope is used to collect secondary electron images and secondary ion mass spectroscopy elemental maps as a function of depth. These images and elemental maps are then used to reconstruct volume image and chemical maps with 20 nm lateral and depth resolutions. Methods to improve lateral resolution and to reduce uncertainties due to differential sputtering are also discussed.