Laser scanning microscope investigation of individual dislocations in as-grown LEC GaAs: geometry, glide, climb and particle decoration

摘要

We have used the LSM to make a comprehensive study of dislocations present in as-grown In-doped and undoped LEC SI GaAs. These dislocations had mainly arisen by glide from the surface to the interior of the ingot, followed by climb and particle decoration, during the growth and subsequent cooling of the ingot. The observations that were made included large abrupt changes in particle decoration as individual dislocations changed direction, dislocation segments with complex cross-slip geometries, dislocation segments in the form of large helices, and differences in the dislocations and particle decoration in In-doped and undoped ingots. Mechanisms to explain these behaviours are described.