X‐Ray Topography—More than Nice Pictures

Abstract

X‐ray topography—a well‐known diffraction imaging method—is widely used for the characterization of extended crystal defects like dislocations. Herein, the progress toward the quantification besides the number and nature of dislocations is given. The diffracted images include additional information about tilt and strain, which can be measured in real‐time, thanks to the improved digital detection systems. This allows not only the fast mapping of huge samples like 450 mm diameter Si wafers, the in situ observation of the dislocation, or crack dynamics at high temperatures, but also the stress analysis in electronic devices in operando. In addition to typical white X‐ray beam methods like stacks of section topographs, the monochromatic diffraction laminography allows a 3D representation of the dislocation arrays. The merits and limitations of X‐ray topography are demonstrated by semiconductor materials as an example.

X-ray Diffraction Topography (Imaging) of Crystals Grown from Solution: A Short Review

“…Full details of X-ray topography methods and analysis can be found in books by the present author, − and there are more recent short reviews of techniques and applications . Therefore, only those techniques most frequently associated with analysis of crystals grown from solution will be described in this section, these also being those which John Sherwood and colleagues used regularly.…”

Dislocation Climb in AlN Crystals Grown at Low-Temperature Gradients Revealed by 3D X-ray Diffraction Imaging

“…The contrast of crystalline defects observed by X-ray diffraction imaging is generated by the local variation of the diffraction condition (e.g., local angular shift of the Bragg condition) induced by lattice deformations surrounding these defects. To study the type of dislocations, the extinction rule g · b = 0 is widely used, , which states that dislocations are not (or hardly) visible if the diffraction vector g is perpendicular to the Burgers vector b . While g · b = 0 is sufficient to render screw dislocations invisible, both g · b = 0 and g ·( b × l ) = 0 are required criteria for edge dislocations, and mixed dislocations are never completely invisible .…”

Analytical Methods for Superresolution Dislocation Identification in Dark-Field X-ray Microscopy

“…As such, our ability to test models for crystal plasticity are limited for macroscopic materials. X-ray imaging methods like X-ray topography and radiography can directly measure the relevant subsurface dynamics, but have long suffered from ambiguity in interpretation for high dislocation-density metals, due to their limitations in spatial resolution [1,3].…”