Three-dimensional structure of dislocations in silicon determined by synchrotron white x-ray topography combined with a topo-tomographic technique

Abstract

We have studied the propagation and elimination of dislocations generated at the early stage of Czochralski silicon crystal growth using synchrotron white x-ray topography combined with a topo-tomographic technique. Two silicon crystals with [001] growth-axes were examined. One was intentionally grown without enlarging its diameter to easily observe the features of the dislocation propagation, and the other was grown with Dash necking, followed by a 2 inch enlargement of its diameter in order to observe the elimination of the dislocations. The three-dimensional structure of the individual dislocation, i.e. the direction of the dislocation line, its Burgers vector and the glide plane, were determined. These investigations revealed that dislocation half loops, which were generated from tangled dislocations, were expanded on their glide planes and were often deformed by their interaction, cross slip and collision with the crystal surface, followed by a gradual decrease in their density. The dislocation-elimination effect of the Dash necking was caused by the expansion of the dislocation half loops being terminated within the crystal and by their pinning on the crystal surface.

Development of white and monochromatic X‐ray topography system in SAGA‐LS

“…Dash‐necking is usually employed in Si crystal growth technology to remove dislocations that form and propagate in a grown crystal. To understand the mechanism of dislocation elimination in the grown crystal, it is necessary to examine its neck (3–7 mm ϕ ) nondestructively 11, 12.…”

“…The test sample used in this experiment was a [001]‐oriented Si rod about 7 mm in diameter, which was grown from a dislocation‐free seed crystal without purposely enlarging its diameter 11, 12. The Si channel‐cut monochromator was removed from the beam path to irradiate the sample with a white X‐ray beam.…”

Three-dimensional X-ray topographic characterization of broken and unbroken natural diamond anvil crystals at 99.4 GPa

“…Many methods have been proposed to overcome this problem. [41][42][43][44][45][46][47] Andersen and Gerward reported the reconstruction of many limited projection topographs taken with step-scanning of a specimen crystal. 48) Recently, Kajiwara et al applied 3D topography to the dislocation distribution of a necking area in a Czochralski grown silicon single crystal with a low dislocation density using white X-rays from a synchrotron radiation source.…”

Three-dimensional X-ray diffraction imaging of process-induced dislocation loops in silicon

“…White-beam synchrotron X-ray topography is a widely used nondestructive characterization technique for the visualization of defects and the characterization of both long-range and short-range strain in crystals (Authier et al, 1996;Danilewsky et al, 2003Danilewsky et al, , 2008Authier, 2004) The most widely used technique for the study of crystal characteristics is transmission topography in the Laue condition in both large-area and section transmission (Guinier & Tennevin, 1949;Kawado et al, 2005;Lang, 1959a,b). This technique was later expanded with the use of synchrotron radiation to obtain high-resolution topographs by Tuomi et al (1974) and Hart (1975).…”

“…Early three-dimensional characterization techniques involved the use of stereo topographs recorded as a pair in the hkl and hkl reflections (Lang, 1959b) or the use of stepscanning section topography (Kawado & Aoyama, 1979), the latter technique requiring the use of an automatic Bragg angle corrector. Later techniques evolved into combined topography and tomography (Ludwig et al, 2001;Kawado et al, 2004Kawado et al, , 2005, and references therein), an approach that consisted of recording a series of images while rotating the sample around its diffraction vector. The application of imaging software to combine the section topographs has also been employed, freeing the researcher from the tedious pen and pencil approach used previously (Mukaide et al, 2006).…”