Formation and properties of In–Te pairs in Si

Abstract

Owing to the Coulomb attraction, oppositely charged impurities in semiconductors tend to form pairs when they become mobile. We employed the perturbed angular correlation probe 111In as an acceptor impurity and studied its interaction with the group VI elements S, Se and Te in Si. They were implanted at room temperature and subsequently the samples were annealed at increasing temperatures in order to remove the implantation-induced damage and increase the mobility of the impurities. After the S and Se implantations, no pair formation was observed. For Te however, a new quadrupole interaction frequency of νQ=444(1)MHz (η=0) was found, which was attributed to the trapping of a Te atom at the In probe. The formation probability of the In–Te pair and the orientation of the corresponding electric field gradient were studied. The observed properties are compatible with the assumption that a complex between a substitutional In acceptor and a Te atom in the adjacent octahedral interstitial site is formed.