Optimal experimental design of STEM measurement of atom column positions

• Published in: Ultramicroscopy Vol. 90; no. 4; pp. 273 - 289
• Main Authors: Van Aert, S., den Dekker, A.J., Van Dyck, D., van den Bos, A.
• Format: Journal Article
• Language: English
• Published: Amsterdam Elsevier B.V 01.04.2002; Elsevier Science
• Subjects: Computers in experimental physics; Condensed matter: structure, mechanical and thermal properties; Data processing/image processing; Design of experiments; Electron microscope design and characterization; Electron, ion, and scanning probe microscopy; Electron, positron and ion microscopes, electron diffractometers and related techniques; Exact sciences and technology; Instruments, apparatus, components and techniques common to several branches of physics and astronomy; Physics; Scanning transmission electron microscopy (STEM); Structure of solids and liquids; crystallography; Transmission, reflection and scanning electron microscopy(including ebic); 61.16.Bg; Data processing/image processing; 02.50.−r; 07.05.FB; Scanning transmission electron microscopy (STEM); Subject index terms: 008; 43.50.+y; Electron microscope design and characterization; 041; 031; Design; Strontium; Gold; Image processing; Tin; Measuring methods; Silicon; Copper; Scanning transmission electron microscopy; High-resolution methods
• ISSN: 0304-3991; 1879-2723
• DOI: 10.1016/S0304-3991(01)00152-8

A quantitative measure is proposed to evaluate and optimize the design of a high-resolution scanning transmission electron microscopy (STEM) experiment. The proposed measure is related to the measurement of atom column positions. Specifically, it is based on the statistical precision with which the positions of atom columns can be estimated. The optimal design, that is, the combination of tunable microscope parameters for which the precision is highest, is derived for different types of atom columns. The proposed measure is also used to find out if an annular detector is preferable to an axial one and if a C s-corrector pays off in quantitative STEM experiments. In addition, the optimal settings of the STEM are compared to the Scherzer conditions for incoherent imaging and their dependence on the type of object is investigated.