Dislocation Elimination in Czochralski Silicon Crystal Growth Revealed by White X‐ray Topography Combined with Topo‐tomographic Technique

We have examined the neck of a large-diameter [001]-oriented Czochralski silicon crystal by synchrotron white X-ray topography combined with a topo-tomographic technique in order to explain the mechanism of dislocation elimination due to Dash necking in industrial-scale crystal growth. In the portion where the grown crystal was transformed from a dislocated region to a dislocation-free region, dislocation half loops were first generated at the dislocation tangles. These loops then expanded on the {111} glide planes and then terminated inside the crystal. In some cases, they reached the side of the crystal. A new mechanism for the elimination of dislocations is proposed based on the fact that dislocations in the neck are not accompanied by the solid-melt interface during the crystal growth, and they proceed in the crystal after the movement of the interface.