Defect structures in InP crystals by laser scanning tomography

Laser-beam scanning tomography images are taken from various InP crystals. They all display a distribution of bright points which are shown to be statistically arranged along the crystallographic axes and . These microdefects are likely distributed along dislocations in such a way that small volumes or “cells” (typically 200-500 µm wide) are kept free from defects. It is shown that the density of defects varies with the doping of the material; lower densities were observed in Fe-doped InP crystals.