US Patent 10403469 Method of performing tomographic imaging in a charged-particle microscope

A method is presented for sub-surface imaging of a specimen in a charged particle microscope. A series of images, with individual members In is collected, with a value of a beam parameter P varied for each image, thereby compiling a measurement set M={(In, Pn)}, with P being the focus position along the charged particle axis. The data for the images are recorded using signals from a segmented detector. The signals from segments combined and compiled to yield a vector field. Mathematical processing then deconvolves the vector field, resulting in depth-resolved imagery of the specimen.