Impurity Reaction with Dislocations in Semiconductors

Basic aspects of impurity reaction with dislocations in semiconductors are discussed on the basis of the work of the author's group. Some important insights into the mechanism of impurity reaction with extended structural defects are deduced from a theoretical treatment of impurity distribution around a structural defect in thermal equilibrium, experimental observations on dislocation pinning, and the characteristics in the development of precipitates on various types of structural defects. The morphology of impurity precipitates formed on a dislocation plays an important role in the strength of dislocation pinning. Generally, the impurity±dislocation reaction is dependent on the species and concentration of impurities as well as the core structure of dislocation, and also on the thermal process of the crystal, i.e. the cooling rate from high temperature.