Three‐dimensional topography using an X‐ray microbeam and novel slit technique

Abstract

This paper describes section topography using an X‐ray microbeam and a novel slit having a V‐shaped crevice (V‐slit). The V‐slit is characterized by a sharp‐pointed exponential transmission curve, which enables depth‐resolved imaging with high spatial resolution. An iterative deconvolution for image restoration is effectively executable, providing submicron resolution in cross‐sectional diffraction imaging. The new method is applied to the analysis of screw dislocation in a SiC diode. (© 2007 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)

Characterization of Screw Dislocations in a 4H-Silicon Carbide Diode Using X-Ray Microbeam Three-Dimensional Topography

“…1). The V-slit is a metal contact made of tungsten (W) with polished slanted edges and an opening angle of 20° [2]. We used Bragg-case geometry with 0 0 16 reflection, in which the scattering vector is parallel to the c-axis.…”

“…However, the mechanism of MB is not fully understood, such as the largely different current-leak levels among similar SDs. In order to better understand the MB phenomena, we conducted crystallographic analysis of SDs in SiC diodes using X-ray microbeam three-dimensional (3D) topography that we have developed [2]. Unlike conventional methods, 3D topography can provide highly depth-resolved strain maps in various cross sections of semiconductor materials.…”

Anomalous extinction of X-rays diffracted in strongly deformed crystals

“…It should be noted that the new X-ray diffraction methods used to study materials in small dimensions (such as coherent diffraction, microdiffraction, X-ray diffraction line-profile modeling etc.) show that such small crystals may be found in states of very high stress (Robinson & Vartanyants, 2001;Tanuma et al, 2007;Scardi, 2004). In this connection it is assumed that the crystals are also strongly deformed.…”

X-ray Microbeam Three-Dimensional Topography Imaging and Strain Analysis of Basal-Plane Dislocations and Threading Edge Dislocations in 4H-SiC

“…2) X-ray microbeam three-dimensional (3D) topography enables us to investigate the behavior of dislocations near a deep E/S interface. 3) This method has been successfully applied to characterize threading screw dislocations (TSDs) in 4H-SiC. 3,4) This paper describes the application of X-ray microbeam 3D topography to BPDs and TEDs, providing stereographic imaging and strain analysis of the dislocations as well as a discussion on image formation in 3D topography.…”

“…The V-slit is made of two tungsten-carbide (WC) knives contacting each other on their tips. 3,4) The knife edges are obliquely cut and polished to make an opening angle of 20 . The V-slit was located 20-30 mm downstream of the sample, and the distance from the V-slit to a receiving slit (RS) was about 400 mm.…”