Positron annihilation at dislocations and related point defects in semiconductors

Dislocations act in semiconductors as combined positron traps, consisting o f a shallow precursor state, which is related to regular parts of the dislo cation line, and bound vacancy-like defects. The motion of dislocations dur ing plastic deformation generates a high number of point defects. The clust ering of vacancies to stable voids is regarded as a primary process of the jog dragging mechanism. Vacancy densities were quantitatively determined fo r different deformation conditions of GaAs.