Imaging thick objects with deep-subangstrom resolution and deep-subpicometer precision

Source: PubMed Central Open Access, NCBI / U.S. National Library of Medicine

Size effects are ubiquitous in the structural, mechanical, and physical properties of materials, making it highly desirable to study the intrinsic properties of thick objects through high-resolution structural analysis in transmission electron microscopy. Although deep-subangstrom resolution has been achieved with multislice electron ptychography, the sample thickness is typically very limited. By combining energy filtering and extended local-orbital ptychography (eLOP) that retrieves varying aberrations during electron beam scanning, here, we report ptychographic reconstructions for silicon as thick as 85 nanometers, approximately three times larger than usual thickness threshold for conventional multislice electron ptychography. The elimination of aberration variations contributes to accurate reconstructions with an information limit of 18 picometers and atomic position precision of 0.39 picometers. Accurate ptychographic reconstructions for thick objects can facilitate the discovery or interpretation of intrinsic structural and physical phenomena in solids, which is of great importance in physics, chemistry, materials science, and semiconductor device engineering. Atomic-scale imaging of thick objects opens the door to discovering intrinsic properties and phenomena in a wide range of solids. teaser