Role of Impurities in Reducing Grown-in Dislocations in Compound Semiconductor Crystals

Abstract

ABSTRACTlmpurity effects on the mobility of dislocations and dislocation generation from generation centers in III - V compound semiconductor crystals are first reviewed on the basis of experimental observations of dynamic behavior of individual dislocations. Dislocation multiplication process is then discussed to account for experimental stress-strain characteristics of these materials obtained in mechanical tests. Using all of such knowledge on dislocation processes in the compound semiconductor crystals, an argument is developed to show how impurities play the role in reducing grown-in dislocations in crystals of these materials. It is shown that immobilization of dislocations caused by impurity gettering plays the decisive role and results in even the growth of dislocation-free crystals.