Simultaneous orientation and thickness mapping in transmission electron microscopy

Abstract

In this paper we introduce an approach for simultaneous thickness and orientation mapping of crystalline samples by means of transmission electron microscopy. We show that local thickness and orientation values can be extracted from experimental dark-field (DF) image data acquired at different specimen tilts. The method has been implemented to automatically acquire the necessary data and then map thickness and crystal orientation for a given region of interest. We have applied this technique to a specimen prepared from a commercial semiconductor device, containing multiple 22 nm technology transistor structures. The performance and limitations of our method are discussed and compared to those of other techniques available.

Two-dimensional misorientation mapping by rocking dark-field transmission electron microscopy

“…The precision of the current technique is expected to be very similar to that of our previous method [24] which relies on fitting DF tilt series data by a Gaussian, and the precision of which has been determined to be 1 mrad < . The accuracy of the orientation mapping depends on the accuracy of the calibration of the goniometer tilt 1 mrad ( < ) and the calibration of the beam tilt 1 mrad ( < ).…”

“…However, this approach is not accurate when the rocking curve exhibits some skewness or has multiple maxima. Fitting of a Gaussian function by the method of non-linear-least-squares as suggested in [24] can accurately estimate the position of rocking curve maxima, but, for large, unbinned data sets, this approach becomes computationally very expensive and slow, especially if multiple reflections are taken into account, as in the present work. To determine the positions of the maxima, we chose the statistical method of moments.…”

“…The orientation maps obtained by the approach introduced above can be used as an improved starting guess compared to our earlier work [24] for a three-dimensional Bloch-wave refinement algorithm recently developed by Pennington and co-workers [31,32].…”

“…Most of the image processing was done in MATLAB using an interactive application developed in-house, featuring a graphical user interface. The functionality of this interface was extended from our previous work [24].…”

Application of Transmitted Kikuchi Diffraction in Studying Nano-oxide and Ultrafine Metallic Grains

“…Although comparable high-resolution orientation mapping techniques based on transmission electron microscopy (TEM) and scanning transmission electron microscopy (STEM) have been introduced, their lack of automation in performing large-scale measurements has played a role in the growth of TKD. These techniques utilize various modes such as spot and Kikuchi diffractions to obtain crystallographic orientations in TEM/STEM. − A newly developed automated package called ASTAR has become available that utilizes a precession diffraction mode combined with template matching to extract crystallographic orientations in TEM. , This technique was used on a nano-oxide sample in the present research. ASTAR and TKD results on ultrafine-grained and nanograined samples are compared and discussed in the upcoming sections.…”