Strain analysis from nano-beam electron diffraction: Influence of specimen tilt and beam convergence.

Strain analyses from experimental series of nano-beam electron diffraction (NBED) patterns in scanning transmission electron microscopy are performed for different specimen tilts. Simulations of NBED series are presented for which strain analysis gives results that are in accordance with experiment. This consequently allows to study the relation between measured strain and actual underlying strain.

Optimization of NBED simulations for disc-detection measurements.

Nano-beam electron diffraction (NBED) is a method which can be applied to measure lattice strain and polarisation fields in strained layer heterostructures and transistors. To investigate precision, accuracy and spatial resolution of such measurements in dependence of properties of the specimen as well as electron optical parameters, simulations of NBED patterns are required which allow to predict the result of common disc-detection algorithms. In this paper we demonstrate by focusing on the detection of the central disc in crystalline silicon that such simulations require to take several experimental characteristics into account in order to obtain results which are comparable to those from experimental NBED patterns.

Theoretical study of precision and accuracy of strain analysis by nano-beam electron diffraction.

Measurement of lattice strain is important to characterize semiconductor nanostructures. As strain has large influence on the electronic band structure, methods for the measurement of strain with high precision, accuracy and spatial resolution in a large field of view are mandatory. In this paper we present a theoretical study of precision and accuracy of measurement of strain by convergent nano-beam electron diffraction.

Comparison of intensity and absolute contrast of simulated and experimental high-resolution transmission electron microscopy images for different multislice simulation methods.

The Stobbs factor problem, a major difference of absolute contrast between experimental and simulated high resolution transmission electron microscopy images has been reported frequently. In this respect, some modifications to the multislice simulation techniques were proposed to improve the correspondence to the experiment. The influence of different suggestions on the simulated contrast is investigated by numerical simulations.